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backend/node_modules/svgo/plugins/_path.js

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+'use strict';
+
+/**
+ * @typedef {import('../lib/types').XastElement} XastElement
+ * @typedef {import('../lib/types').PathDataItem} PathDataItem
+ */
+
+const { parsePathData, stringifyPathData } = require('../lib/path.js');
+
+/**
+ * @type {[number, number]}
+ */
+var prevCtrlPoint;
+
+/**
+ * Convert path string to JS representation.
+ *
+ * @type {(path: XastElement) => PathDataItem[]}
+ */
+const path2js = (path) => {
+  // @ts-ignore legacy
+  if (path.pathJS) return path.pathJS;
+  /**
+   * @type {PathDataItem[]}
+   */
+  const pathData = []; // JS representation of the path data
+  const newPathData = parsePathData(path.attributes.d);
+  for (const { command, args } of newPathData) {
+    pathData.push({ command, args });
+  }
+  // First moveto is actually absolute. Subsequent coordinates were separated above.
+  if (pathData.length && pathData[0].command == 'm') {
+    pathData[0].command = 'M';
+  }
+  // @ts-ignore legacy
+  path.pathJS = pathData;
+  return pathData;
+};
+exports.path2js = path2js;
+
+/**
+ * Convert relative Path data to absolute.
+ *
+ * @type {(data: PathDataItem[]) => PathDataItem[]}
+ *
+ */
+const convertRelativeToAbsolute = (data) => {
+  /**
+   * @type {PathDataItem[]}
+   */
+  const newData = [];
+  let start = [0, 0];
+  let cursor = [0, 0];
+
+  for (let { command, args } of data) {
+    args = args.slice();
+
+    // moveto (x y)
+    if (command === 'm') {
+      args[0] += cursor[0];
+      args[1] += cursor[1];
+      command = 'M';
+    }
+    if (command === 'M') {
+      cursor[0] = args[0];
+      cursor[1] = args[1];
+      start[0] = cursor[0];
+      start[1] = cursor[1];
+    }
+
+    // horizontal lineto (x)
+    if (command === 'h') {
+      args[0] += cursor[0];
+      command = 'H';
+    }
+    if (command === 'H') {
+      cursor[0] = args[0];
+    }
+
+    // vertical lineto (y)
+    if (command === 'v') {
+      args[0] += cursor[1];
+      command = 'V';
+    }
+    if (command === 'V') {
+      cursor[1] = args[0];
+    }
+
+    // lineto (x y)
+    if (command === 'l') {
+      args[0] += cursor[0];
+      args[1] += cursor[1];
+      command = 'L';
+    }
+    if (command === 'L') {
+      cursor[0] = args[0];
+      cursor[1] = args[1];
+    }
+
+    // curveto (x1 y1 x2 y2 x y)
+    if (command === 'c') {
+      args[0] += cursor[0];
+      args[1] += cursor[1];
+      args[2] += cursor[0];
+      args[3] += cursor[1];
+      args[4] += cursor[0];
+      args[5] += cursor[1];
+      command = 'C';
+    }
+    if (command === 'C') {
+      cursor[0] = args[4];
+      cursor[1] = args[5];
+    }
+
+    // smooth curveto (x2 y2 x y)
+    if (command === 's') {
+      args[0] += cursor[0];
+      args[1] += cursor[1];
+      args[2] += cursor[0];
+      args[3] += cursor[1];
+      command = 'S';
+    }
+    if (command === 'S') {
+      cursor[0] = args[2];
+      cursor[1] = args[3];
+    }
+
+    // quadratic Bézier curveto (x1 y1 x y)
+    if (command === 'q') {
+      args[0] += cursor[0];
+      args[1] += cursor[1];
+      args[2] += cursor[0];
+      args[3] += cursor[1];
+      command = 'Q';
+    }
+    if (command === 'Q') {
+      cursor[0] = args[2];
+      cursor[1] = args[3];
+    }
+
+    // smooth quadratic Bézier curveto (x y)
+    if (command === 't') {
+      args[0] += cursor[0];
+      args[1] += cursor[1];
+      command = 'T';
+    }
+    if (command === 'T') {
+      cursor[0] = args[0];
+      cursor[1] = args[1];
+    }
+
+    // elliptical arc (rx ry x-axis-rotation large-arc-flag sweep-flag x y)
+    if (command === 'a') {
+      args[5] += cursor[0];
+      args[6] += cursor[1];
+      command = 'A';
+    }
+    if (command === 'A') {
+      cursor[0] = args[5];
+      cursor[1] = args[6];
+    }
+
+    // closepath
+    if (command === 'z' || command === 'Z') {
+      cursor[0] = start[0];
+      cursor[1] = start[1];
+      command = 'z';
+    }
+
+    newData.push({ command, args });
+  }
+  return newData;
+};
+
+/**
+ * @typedef {{ floatPrecision?: number, noSpaceAfterFlags?: boolean }} Js2PathParams
+ */
+
+/**
+ * Convert path array to string.
+ *
+ * @type {(path: XastElement, data: PathDataItem[], params: Js2PathParams) => void}
+ */
+exports.js2path = function (path, data, params) {
+  // @ts-ignore legacy
+  path.pathJS = data;
+
+  const pathData = [];
+  for (const item of data) {
+    // remove moveto commands which are followed by moveto commands
+    if (
+      pathData.length !== 0 &&
+      (item.command === 'M' || item.command === 'm')
+    ) {
+      const last = pathData[pathData.length - 1];
+      if (last.command === 'M' || last.command === 'm') {
+        pathData.pop();
+      }
+    }
+    pathData.push({
+      command: item.command,
+      args: item.args,
+    });
+  }
+
+  path.attributes.d = stringifyPathData({
+    pathData,
+    precision: params.floatPrecision,
+    disableSpaceAfterFlags: params.noSpaceAfterFlags,
+  });
+};
+
+/**
+ * @type {(dest: number[], source: number[]) => number[]}
+ */
+function set(dest, source) {
+  dest[0] = source[source.length - 2];
+  dest[1] = source[source.length - 1];
+  return dest;
+}
+
+/**
+ * Checks if two paths have an intersection by checking convex hulls
+ * collision using Gilbert-Johnson-Keerthi distance algorithm
+ * https://web.archive.org/web/20180822200027/http://entropyinteractive.com/2011/04/gjk-algorithm/
+ *
+ * @type {(path1: PathDataItem[], path2: PathDataItem[]) => boolean}
+ */
+exports.intersects = function (path1, path2) {
+  // Collect points of every subpath.
+  const points1 = gatherPoints(convertRelativeToAbsolute(path1));
+  const points2 = gatherPoints(convertRelativeToAbsolute(path2));
+
+  // Axis-aligned bounding box check.
+  if (
+    points1.maxX <= points2.minX ||
+    points2.maxX <= points1.minX ||
+    points1.maxY <= points2.minY ||
+    points2.maxY <= points1.minY ||
+    points1.list.every((set1) => {
+      return points2.list.every((set2) => {
+        return (
+          set1.list[set1.maxX][0] <= set2.list[set2.minX][0] ||
+          set2.list[set2.maxX][0] <= set1.list[set1.minX][0] ||
+          set1.list[set1.maxY][1] <= set2.list[set2.minY][1] ||
+          set2.list[set2.maxY][1] <= set1.list[set1.minY][1]
+        );
+      });
+    })
+  )
+    return false;
+
+  // Get a convex hull from points of each subpath. Has the most complexity O(n·log n).
+  const hullNest1 = points1.list.map(convexHull);
+  const hullNest2 = points2.list.map(convexHull);
+
+  // Check intersection of every subpath of the first path with every subpath of the second.
+  return hullNest1.some(function (hull1) {
+    if (hull1.list.length < 3) return false;
+
+    return hullNest2.some(function (hull2) {
+      if (hull2.list.length < 3) return false;
+
+      var simplex = [getSupport(hull1, hull2, [1, 0])], // create the initial simplex
+        direction = minus(simplex[0]); // set the direction to point towards the origin
+
+      var iterations = 1e4; // infinite loop protection, 10 000 iterations is more than enough
+      // eslint-disable-next-line no-constant-condition
+      while (true) {
+        if (iterations-- == 0) {
+          console.error(
+            'Error: infinite loop while processing mergePaths plugin.',
+          );
+          return true; // true is the safe value that means “do nothing with paths”
+        }
+        // add a new point
+        simplex.push(getSupport(hull1, hull2, direction));
+        // see if the new point was on the correct side of the origin
+        if (dot(direction, simplex[simplex.length - 1]) <= 0) return false;
+        // process the simplex
+        if (processSimplex(simplex, direction)) return true;
+      }
+    });
+  });
+
+  /**
+   * @type {(a: Point, b: Point, direction: number[]) => number[]}
+   */
+  function getSupport(a, b, direction) {
+    return sub(supportPoint(a, direction), supportPoint(b, minus(direction)));
+  }
+
+  // Computes farthest polygon point in particular direction.
+  // Thanks to knowledge of min/max x and y coordinates we can choose a quadrant to search in.
+  // Since we're working on convex hull, the dot product is increasing until we find the farthest point.
+  /**
+   * @type {(polygon: Point, direction: number[]) => number[]}
+   */
+  function supportPoint(polygon, direction) {
+    var index =
+        direction[1] >= 0
+          ? direction[0] < 0
+            ? polygon.maxY
+            : polygon.maxX
+          : direction[0] < 0
+            ? polygon.minX
+            : polygon.minY,
+      max = -Infinity,
+      value;
+    while ((value = dot(polygon.list[index], direction)) > max) {
+      max = value;
+      index = ++index % polygon.list.length;
+    }
+    return polygon.list[(index || polygon.list.length) - 1];
+  }
+};
+
+/**
+ * @type {(simplex: number[][], direction: number[]) => boolean}
+ */
+function processSimplex(simplex, direction) {
+  // we only need to handle to 1-simplex and 2-simplex
+  if (simplex.length == 2) {
+    // 1-simplex
+    let a = simplex[1],
+      b = simplex[0],
+      AO = minus(simplex[1]),
+      AB = sub(b, a);
+    // AO is in the same direction as AB
+    if (dot(AO, AB) > 0) {
+      // get the vector perpendicular to AB facing O
+      set(direction, orth(AB, a));
+    } else {
+      set(direction, AO);
+      // only A remains in the simplex
+      simplex.shift();
+    }
+  } else {
+    // 2-simplex
+    let a = simplex[2], // [a, b, c] = simplex
+      b = simplex[1],
+      c = simplex[0],
+      AB = sub(b, a),
+      AC = sub(c, a),
+      AO = minus(a),
+      ACB = orth(AB, AC), // the vector perpendicular to AB facing away from C
+      ABC = orth(AC, AB); // the vector perpendicular to AC facing away from B
+
+    if (dot(ACB, AO) > 0) {
+      if (dot(AB, AO) > 0) {
+        // region 4
+        set(direction, ACB);
+        simplex.shift(); // simplex = [b, a]
+      } else {
+        // region 5
+        set(direction, AO);
+        simplex.splice(0, 2); // simplex = [a]
+      }
+    } else if (dot(ABC, AO) > 0) {
+      if (dot(AC, AO) > 0) {
+        // region 6
+        set(direction, ABC);
+        simplex.splice(1, 1); // simplex = [c, a]
+      } else {
+        // region 5 (again)
+        set(direction, AO);
+        simplex.splice(0, 2); // simplex = [a]
+      }
+    } // region 7
+    else return true;
+  }
+  return false;
+}
+
+/**
+ * @type {(v: number[]) => number[]}
+ */
+function minus(v) {
+  return [-v[0], -v[1]];
+}
+
+/**
+ * @type {(v1: number[], v2: number[]) => number[]}
+ */
+function sub(v1, v2) {
+  return [v1[0] - v2[0], v1[1] - v2[1]];
+}
+
+/**
+ * @type {(v1: number[], v2: number[]) => number}
+ */
+function dot(v1, v2) {
+  return v1[0] * v2[0] + v1[1] * v2[1];
+}
+
+/**
+ * @type {(v1: number[], v2: number[]) => number[]}
+ */
+function orth(v, from) {
+  var o = [-v[1], v[0]];
+  return dot(o, minus(from)) < 0 ? minus(o) : o;
+}
+
+/**
+ * @typedef {{
+ *   list: number[][],
+ *   minX: number,
+ *   minY: number,
+ *   maxX: number,
+ *   maxY: number
+ * }} Point
+ */
+
+/**
+ * @typedef {{
+ *   list: Point[],
+ *   minX: number,
+ *   minY: number,
+ *   maxX: number,
+ *   maxY: number
+ * }} Points
+ */
+
+/**
+ * @type {(pathData: PathDataItem[]) => Points}
+ */
+function gatherPoints(pathData) {
+  /**
+   * @type {Points}
+   */
+  const points = { list: [], minX: 0, minY: 0, maxX: 0, maxY: 0 };
+
+  // Writes data about the extreme points on each axle
+  /**
+   * @type {(path: Point, point: number[]) => void}
+   */
+  const addPoint = (path, point) => {
+    if (!path.list.length || point[1] > path.list[path.maxY][1]) {
+      path.maxY = path.list.length;
+      points.maxY = points.list.length
+        ? Math.max(point[1], points.maxY)
+        : point[1];
+    }
+    if (!path.list.length || point[0] > path.list[path.maxX][0]) {
+      path.maxX = path.list.length;
+      points.maxX = points.list.length
+        ? Math.max(point[0], points.maxX)
+        : point[0];
+    }
+    if (!path.list.length || point[1] < path.list[path.minY][1]) {
+      path.minY = path.list.length;
+      points.minY = points.list.length
+        ? Math.min(point[1], points.minY)
+        : point[1];
+    }
+    if (!path.list.length || point[0] < path.list[path.minX][0]) {
+      path.minX = path.list.length;
+      points.minX = points.list.length
+        ? Math.min(point[0], points.minX)
+        : point[0];
+    }
+    path.list.push(point);
+  };
+
+  for (let i = 0; i < pathData.length; i += 1) {
+    const pathDataItem = pathData[i];
+    let subPath =
+      points.list.length === 0
+        ? { list: [], minX: 0, minY: 0, maxX: 0, maxY: 0 }
+        : points.list[points.list.length - 1];
+    let prev = i === 0 ? null : pathData[i - 1];
+    let basePoint =
+      subPath.list.length === 0 ? null : subPath.list[subPath.list.length - 1];
+    let data = pathDataItem.args;
+    let ctrlPoint = basePoint;
+
+    /**
+     * @type {(n: number, i: number) => number}
+     * TODO fix null hack
+     */
+    const toAbsolute = (n, i) => n + (basePoint == null ? 0 : basePoint[i % 2]);
+
+    switch (pathDataItem.command) {
+      case 'M':
+        subPath = { list: [], minX: 0, minY: 0, maxX: 0, maxY: 0 };
+        points.list.push(subPath);
+        break;
+
+      case 'H':
+        if (basePoint != null) {
+          addPoint(subPath, [data[0], basePoint[1]]);
+        }
+        break;
+
+      case 'V':
+        if (basePoint != null) {
+          addPoint(subPath, [basePoint[0], data[0]]);
+        }
+        break;
+
+      case 'Q':
+        addPoint(subPath, data.slice(0, 2));
+        prevCtrlPoint = [data[2] - data[0], data[3] - data[1]]; // Save control point for shorthand
+        break;
+
+      case 'T':
+        if (
+          basePoint != null &&
+          prev != null &&
+          (prev.command == 'Q' || prev.command == 'T')
+        ) {
+          ctrlPoint = [
+            basePoint[0] + prevCtrlPoint[0],
+            basePoint[1] + prevCtrlPoint[1],
+          ];
+          addPoint(subPath, ctrlPoint);
+          prevCtrlPoint = [data[0] - ctrlPoint[0], data[1] - ctrlPoint[1]];
+        }
+        break;
+
+      case 'C':
+        if (basePoint != null) {
+          // Approximate quibic Bezier curve with middle points between control points
+          addPoint(subPath, [
+            0.5 * (basePoint[0] + data[0]),
+            0.5 * (basePoint[1] + data[1]),
+          ]);
+        }
+        addPoint(subPath, [
+          0.5 * (data[0] + data[2]),
+          0.5 * (data[1] + data[3]),
+        ]);
+        addPoint(subPath, [
+          0.5 * (data[2] + data[4]),
+          0.5 * (data[3] + data[5]),
+        ]);
+        prevCtrlPoint = [data[4] - data[2], data[5] - data[3]]; // Save control point for shorthand
+        break;
+
+      case 'S':
+        if (
+          basePoint != null &&
+          prev != null &&
+          (prev.command == 'C' || prev.command == 'S')
+        ) {
+          addPoint(subPath, [
+            basePoint[0] + 0.5 * prevCtrlPoint[0],
+            basePoint[1] + 0.5 * prevCtrlPoint[1],
+          ]);
+          ctrlPoint = [
+            basePoint[0] + prevCtrlPoint[0],
+            basePoint[1] + prevCtrlPoint[1],
+          ];
+        }
+        if (ctrlPoint != null) {
+          addPoint(subPath, [
+            0.5 * (ctrlPoint[0] + data[0]),
+            0.5 * (ctrlPoint[1] + data[1]),
+          ]);
+        }
+        addPoint(subPath, [
+          0.5 * (data[0] + data[2]),
+          0.5 * (data[1] + data[3]),
+        ]);
+        prevCtrlPoint = [data[2] - data[0], data[3] - data[1]];
+        break;
+
+      case 'A':
+        if (basePoint != null) {
+          // Convert the arc to bezier curves and use the same approximation
+          // @ts-ignore no idea what's going on here
+          var curves = a2c.apply(0, basePoint.concat(data));
+          for (
+            var cData;
+            (cData = curves.splice(0, 6).map(toAbsolute)).length;
+
+          ) {
+            if (basePoint != null) {
+              addPoint(subPath, [
+                0.5 * (basePoint[0] + cData[0]),
+                0.5 * (basePoint[1] + cData[1]),
+              ]);
+            }
+            addPoint(subPath, [
+              0.5 * (cData[0] + cData[2]),
+              0.5 * (cData[1] + cData[3]),
+            ]);
+            addPoint(subPath, [
+              0.5 * (cData[2] + cData[4]),
+              0.5 * (cData[3] + cData[5]),
+            ]);
+            if (curves.length) addPoint(subPath, (basePoint = cData.slice(-2)));
+          }
+        }
+        break;
+    }
+
+    // Save final command coordinates
+    if (data.length >= 2) addPoint(subPath, data.slice(-2));
+  }
+
+  return points;
+}
+
+/**
+ * Forms a convex hull from set of points of every subpath using monotone chain convex hull algorithm.
+ * https://en.wikibooks.org/wiki/Algorithm_Implementation/Geometry/Convex_hull/Monotone_chain
+ *
+ * @type {(points: Point) => Point}
+ */
+function convexHull(points) {
+  points.list.sort(function (a, b) {
+    return a[0] == b[0] ? a[1] - b[1] : a[0] - b[0];
+  });
+
+  var lower = [],
+    minY = 0,
+    bottom = 0;
+  for (let i = 0; i < points.list.length; i++) {
+    while (
+      lower.length >= 2 &&
+      cross(lower[lower.length - 2], lower[lower.length - 1], points.list[i]) <=
+        0
+    ) {
+      lower.pop();
+    }
+    if (points.list[i][1] < points.list[minY][1]) {
+      minY = i;
+      bottom = lower.length;
+    }
+    lower.push(points.list[i]);
+  }
+
+  var upper = [],
+    maxY = points.list.length - 1,
+    top = 0;
+  for (let i = points.list.length; i--; ) {
+    while (
+      upper.length >= 2 &&
+      cross(upper[upper.length - 2], upper[upper.length - 1], points.list[i]) <=
+        0
+    ) {
+      upper.pop();
+    }
+    if (points.list[i][1] > points.list[maxY][1]) {
+      maxY = i;
+      top = upper.length;
+    }
+    upper.push(points.list[i]);
+  }
+
+  // last points are equal to starting points of the other part
+  upper.pop();
+  lower.pop();
+
+  const hullList = lower.concat(upper);
+
+  /**
+   * @type {Point}
+   */
+  const hull = {
+    list: hullList,
+    minX: 0, // by sorting
+    maxX: lower.length,
+    minY: bottom,
+    maxY: (lower.length + top) % hullList.length,
+  };
+
+  return hull;
+}
+
+/**
+ * @type {(o: number[], a: number[], b: number[]) => number}
+ */
+function cross(o, a, b) {
+  return (a[0] - o[0]) * (b[1] - o[1]) - (a[1] - o[1]) * (b[0] - o[0]);
+}
+
+/**
+ * Based on code from Snap.svg (Apache 2 license). http://snapsvg.io/
+ * Thanks to Dmitry Baranovskiy for his great work!
+ *
+ * @type {(
+ *  x1: number,
+ *  y1: number,
+ *  rx: number,
+ *  ry: number,
+ *  angle: number,
+ *  large_arc_flag: number,
+ *  sweep_flag: number,
+ *  x2: number,
+ *  y2: number,
+ *  recursive: number[]
+ * ) => number[]}
+ */
+const a2c = (
+  x1,
+  y1,
+  rx,
+  ry,
+  angle,
+  large_arc_flag,
+  sweep_flag,
+  x2,
+  y2,
+  recursive,
+) => {
+  // for more information of where this Math came from visit:
+  // https://www.w3.org/TR/SVG11/implnote.html#ArcImplementationNotes
+  const _120 = (Math.PI * 120) / 180;
+  const rad = (Math.PI / 180) * (+angle || 0);
+  /**
+   * @type {number[]}
+   */
+  let res = [];
+  /**
+   * @type {(x: number, y: number, rad: number) => number}
+   */
+  const rotateX = (x, y, rad) => {
+    return x * Math.cos(rad) - y * Math.sin(rad);
+  };
+  /**
+   * @type {(x: number, y: number, rad: number) => number}
+   */
+  const rotateY = (x, y, rad) => {
+    return x * Math.sin(rad) + y * Math.cos(rad);
+  };
+  if (!recursive) {
+    x1 = rotateX(x1, y1, -rad);
+    y1 = rotateY(x1, y1, -rad);
+    x2 = rotateX(x2, y2, -rad);
+    y2 = rotateY(x2, y2, -rad);
+    var x = (x1 - x2) / 2,
+      y = (y1 - y2) / 2;
+    var h = (x * x) / (rx * rx) + (y * y) / (ry * ry);
+    if (h > 1) {
+      h = Math.sqrt(h);
+      rx = h * rx;
+      ry = h * ry;
+    }
+    var rx2 = rx * rx;
+    var ry2 = ry * ry;
+    var k =
+      (large_arc_flag == sweep_flag ? -1 : 1) *
+      Math.sqrt(
+        Math.abs(
+          (rx2 * ry2 - rx2 * y * y - ry2 * x * x) / (rx2 * y * y + ry2 * x * x),
+        ),
+      );
+    var cx = (k * rx * y) / ry + (x1 + x2) / 2;
+    var cy = (k * -ry * x) / rx + (y1 + y2) / 2;
+    var f1 = Math.asin(Number(((y1 - cy) / ry).toFixed(9)));
+    var f2 = Math.asin(Number(((y2 - cy) / ry).toFixed(9)));
+
+    f1 = x1 < cx ? Math.PI - f1 : f1;
+    f2 = x2 < cx ? Math.PI - f2 : f2;
+    f1 < 0 && (f1 = Math.PI * 2 + f1);
+    f2 < 0 && (f2 = Math.PI * 2 + f2);
+    if (sweep_flag && f1 > f2) {
+      f1 = f1 - Math.PI * 2;
+    }
+    if (!sweep_flag && f2 > f1) {
+      f2 = f2 - Math.PI * 2;
+    }
+  } else {
+    f1 = recursive[0];
+    f2 = recursive[1];
+    cx = recursive[2];
+    cy = recursive[3];
+  }
+  var df = f2 - f1;
+  if (Math.abs(df) > _120) {
+    var f2old = f2,
+      x2old = x2,
+      y2old = y2;
+    f2 = f1 + _120 * (sweep_flag && f2 > f1 ? 1 : -1);
+    x2 = cx + rx * Math.cos(f2);
+    y2 = cy + ry * Math.sin(f2);
+    res = a2c(x2, y2, rx, ry, angle, 0, sweep_flag, x2old, y2old, [
+      f2,
+      f2old,
+      cx,
+      cy,
+    ]);
+  }
+  df = f2 - f1;
+  var c1 = Math.cos(f1),
+    s1 = Math.sin(f1),
+    c2 = Math.cos(f2),
+    s2 = Math.sin(f2),
+    t = Math.tan(df / 4),
+    hx = (4 / 3) * rx * t,
+    hy = (4 / 3) * ry * t,
+    m = [
+      -hx * s1,
+      hy * c1,
+      x2 + hx * s2 - x1,
+      y2 - hy * c2 - y1,
+      x2 - x1,
+      y2 - y1,
+    ];
+  if (recursive) {
+    return m.concat(res);
+  } else {
+    res = m.concat(res);
+    var newres = [];
+    for (var i = 0, n = res.length; i < n; i++) {
+      newres[i] =
+        i % 2
+          ? rotateY(res[i - 1], res[i], rad)
+          : rotateX(res[i], res[i + 1], rad);
+    }
+    return newres;
+  }
+};

backend/node_modules/svgo/plugins/_transforms.js

@@ -0,0 +1,410 @@
+'use strict';
+
+const { toFixed } = require('../lib/svgo/tools');
+
+/**
+ * @typedef {{ name: string, data: number[] }} TransformItem
+ * @typedef {{
+ *   convertToShorts: boolean,
+ *   floatPrecision: number,
+ *   transformPrecision: number,
+ *   matrixToTransform: boolean,
+ *   shortTranslate: boolean,
+ *   shortScale: boolean,
+ *   shortRotate: boolean,
+ *   removeUseless: boolean,
+ *   collapseIntoOne: boolean,
+ *   leadingZero: boolean,
+ *   negativeExtraSpace: boolean,
+ * }} TransformParams
+ */
+
+const transformTypes = new Set([
+  'matrix',
+  'rotate',
+  'scale',
+  'skewX',
+  'skewY',
+  'translate',
+]);
+
+const regTransformSplit =
+  /\s*(matrix|translate|scale|rotate|skewX|skewY)\s*\(\s*(.+?)\s*\)[\s,]*/;
+const regNumericValues = /[-+]?(?:\d*\.\d+|\d+\.?)(?:[eE][-+]?\d+)?/g;
+
+/**
+ * Convert transform string to JS representation.
+ *
+ * @param {string} transformString
+ * @returns {TransformItem[]} Object representation of transform, or an empty array if it was malformed.
+ */
+exports.transform2js = (transformString) => {
+  /** @type {TransformItem[]} */
+  const transforms = [];
+  /** @type {?TransformItem} */
+  let currentTransform = null;
+
+  // split value into ['', 'translate', '10 50', '', 'scale', '2', '', 'rotate', '-45', '']
+  for (const item of transformString.split(regTransformSplit)) {
+    if (!item) {
+      continue;
+    }
+
+    if (transformTypes.has(item)) {
+      currentTransform = { name: item, data: [] };
+      transforms.push(currentTransform);
+    } else {
+      let num;
+      // then split it into [10, 50] and collect as context.data
+      while ((num = regNumericValues.exec(item))) {
+        num = Number(num);
+        if (currentTransform != null) {
+          currentTransform.data.push(num);
+        }
+      }
+    }
+  }
+
+  return currentTransform == null || currentTransform.data.length == 0
+    ? []
+    : transforms;
+};
+
+/**
+ * Multiply transforms into one.
+ *
+ * @param {TransformItem[]} transforms
+ * @returns {TransformItem}
+ */
+exports.transformsMultiply = (transforms) => {
+  const matrixData = transforms.map((transform) => {
+    if (transform.name === 'matrix') {
+      return transform.data;
+    }
+    return transformToMatrix(transform);
+  });
+
+  const matrixTransform = {
+    name: 'matrix',
+    data:
+      matrixData.length > 0 ? matrixData.reduce(multiplyTransformMatrices) : [],
+  };
+
+  return matrixTransform;
+};
+
+/**
+ * Math utilities in radians.
+ */
+const mth = {
+  /**
+   * @param {number} deg
+   * @returns {number}
+   */
+  rad: (deg) => {
+    return (deg * Math.PI) / 180;
+  },
+
+  /**
+   * @param {number} rad
+   * @returns {number}
+   */
+  deg: (rad) => {
+    return (rad * 180) / Math.PI;
+  },
+
+  /**
+   * @param {number} deg
+   * @returns {number}
+   */
+  cos: (deg) => {
+    return Math.cos(mth.rad(deg));
+  },
+
+  /**
+   * @param {number} val
+   * @param {number} floatPrecision
+   * @returns {number}
+   */
+  acos: (val, floatPrecision) => {
+    return toFixed(mth.deg(Math.acos(val)), floatPrecision);
+  },
+
+  /**
+   * @param {number} deg
+   * @returns {number}
+   */
+  sin: (deg) => {
+    return Math.sin(mth.rad(deg));
+  },
+
+  /**
+   * @param {number} val
+   * @param {number} floatPrecision
+   * @returns {number}
+   */
+  asin: (val, floatPrecision) => {
+    return toFixed(mth.deg(Math.asin(val)), floatPrecision);
+  },
+
+  /**
+   * @param {number} deg
+   * @returns {number}
+   */
+  tan: (deg) => {
+    return Math.tan(mth.rad(deg));
+  },
+
+  /**
+   * @param {number} val
+   * @param {number} floatPrecision
+   * @returns {number}
+   */
+  atan: (val, floatPrecision) => {
+    return toFixed(mth.deg(Math.atan(val)), floatPrecision);
+  },
+};
+
+/**
+ * Decompose matrix into simple transforms.
+ *
+ * @param {TransformItem} transform
+ * @param {TransformParams} params
+ * @returns {TransformItem[]}
+ * @see https://frederic-wang.fr/decomposition-of-2d-transform-matrices.html
+ */
+exports.matrixToTransform = (transform, params) => {
+  const floatPrecision = params.floatPrecision;
+  const data = transform.data;
+  const transforms = [];
+
+  // [..., ..., ..., ..., tx, ty] → translate(tx, ty)
+  if (data[4] || data[5]) {
+    transforms.push({
+      name: 'translate',
+      data: data.slice(4, data[5] ? 6 : 5),
+    });
+  }
+
+  let sx = toFixed(Math.hypot(data[0], data[1]), params.transformPrecision);
+  let sy = toFixed(
+    (data[0] * data[3] - data[1] * data[2]) / sx,
+    params.transformPrecision,
+  );
+  const colsSum = data[0] * data[2] + data[1] * data[3];
+  const rowsSum = data[0] * data[1] + data[2] * data[3];
+  const scaleBefore = rowsSum !== 0 || sx === sy;
+
+  // [sx, 0, tan(a)·sy, sy, 0, 0] → skewX(a)·scale(sx, sy)
+  if (!data[1] && data[2]) {
+    transforms.push({
+      name: 'skewX',
+      data: [mth.atan(data[2] / sy, floatPrecision)],
+    });
+
+    // [sx, sx·tan(a), 0, sy, 0, 0] → skewY(a)·scale(sx, sy)
+  } else if (data[1] && !data[2]) {
+    transforms.push({
+      name: 'skewY',
+      data: [mth.atan(data[1] / data[0], floatPrecision)],
+    });
+    sx = data[0];
+    sy = data[3];
+
+    // [sx·cos(a), sx·sin(a), sy·-sin(a), sy·cos(a), x, y] → rotate(a[, cx, cy])·(scale or skewX) or
+    // [sx·cos(a), sy·sin(a), sx·-sin(a), sy·cos(a), x, y] → scale(sx, sy)·rotate(a[, cx, cy]) (if !scaleBefore)
+  } else if (!colsSum || (sx === 1 && sy === 1) || !scaleBefore) {
+    if (!scaleBefore) {
+      sx = Math.hypot(data[0], data[2]);
+      sy = Math.hypot(data[1], data[3]);
+
+      if (toFixed(data[0], params.transformPrecision) < 0) {
+        sx = -sx;
+      }
+
+      if (
+        data[3] < 0 ||
+        (Math.sign(data[1]) === Math.sign(data[2]) &&
+          toFixed(data[3], params.transformPrecision) === 0)
+      ) {
+        sy = -sy;
+      }
+
+      transforms.push({ name: 'scale', data: [sx, sy] });
+    }
+    const angle = Math.min(Math.max(-1, data[0] / sx), 1);
+    const rotate = [
+      mth.acos(angle, floatPrecision) *
+        ((scaleBefore ? 1 : sy) * data[1] < 0 ? -1 : 1),
+    ];
+
+    if (rotate[0]) {
+      transforms.push({ name: 'rotate', data: rotate });
+    }
+
+    if (rowsSum && colsSum)
+      transforms.push({
+        name: 'skewX',
+        data: [mth.atan(colsSum / (sx * sx), floatPrecision)],
+      });
+
+    // rotate(a, cx, cy) can consume translate() within optional arguments cx, cy (rotation point)
+    if (rotate[0] && (data[4] || data[5])) {
+      transforms.shift();
+      const oneOverCos = 1 - data[0] / sx;
+      const sin = data[1] / (scaleBefore ? sx : sy);
+      const x = data[4] * (scaleBefore ? 1 : sy);
+      const y = data[5] * (scaleBefore ? 1 : sx);
+      const denom = (oneOverCos ** 2 + sin ** 2) * (scaleBefore ? 1 : sx * sy);
+      rotate.push(
+        (oneOverCos * x - sin * y) / denom,
+        (oneOverCos * y + sin * x) / denom,
+      );
+    }
+
+    // Too many transformations, return original matrix if it isn't just a scale/translate
+  } else if (data[1] || data[2]) {
+    return [transform];
+  }
+
+  if ((scaleBefore && (sx != 1 || sy != 1)) || !transforms.length) {
+    transforms.push({
+      name: 'scale',
+      data: sx == sy ? [sx] : [sx, sy],
+    });
+  }
+
+  return transforms;
+};
+
+/**
+ * Convert transform to the matrix data.
+ *
+ * @type {(transform: TransformItem) => number[] }
+ */
+const transformToMatrix = (transform) => {
+  if (transform.name === 'matrix') {
+    return transform.data;
+  }
+  switch (transform.name) {
+    case 'translate':
+      // [1, 0, 0, 1, tx, ty]
+      return [1, 0, 0, 1, transform.data[0], transform.data[1] || 0];
+    case 'scale':
+      // [sx, 0, 0, sy, 0, 0]
+      return [
+        transform.data[0],
+        0,
+        0,
+        transform.data[1] || transform.data[0],
+        0,
+        0,
+      ];
+    case 'rotate':
+      // [cos(a), sin(a), -sin(a), cos(a), x, y]
+      var cos = mth.cos(transform.data[0]),
+        sin = mth.sin(transform.data[0]),
+        cx = transform.data[1] || 0,
+        cy = transform.data[2] || 0;
+      return [
+        cos,
+        sin,
+        -sin,
+        cos,
+        (1 - cos) * cx + sin * cy,
+        (1 - cos) * cy - sin * cx,
+      ];
+    case 'skewX':
+      // [1, 0, tan(a), 1, 0, 0]
+      return [1, 0, mth.tan(transform.data[0]), 1, 0, 0];
+    case 'skewY':
+      // [1, tan(a), 0, 1, 0, 0]
+      return [1, mth.tan(transform.data[0]), 0, 1, 0, 0];
+    default:
+      throw Error(`Unknown transform ${transform.name}`);
+  }
+};
+
+/**
+ * Applies transformation to an arc. To do so, we represent ellipse as a matrix, multiply it
+ * by the transformation matrix and use a singular value decomposition to represent in a form
+ * rotate(θ)·scale(a b)·rotate(φ). This gives us new ellipse params a, b and θ.
+ * SVD is being done with the formulae provided by Wolffram|Alpha (svd {{m0, m2}, {m1, m3}})
+ *
+ * @type {(
+ *   cursor: [x: number, y: number],
+ *   arc: number[],
+ *   transform: number[]
+ * ) => number[]}
+ */
+exports.transformArc = (cursor, arc, transform) => {
+  const x = arc[5] - cursor[0];
+  const y = arc[6] - cursor[1];
+  let a = arc[0];
+  let b = arc[1];
+  const rot = (arc[2] * Math.PI) / 180;
+  const cos = Math.cos(rot);
+  const sin = Math.sin(rot);
+  // skip if radius is 0
+  if (a > 0 && b > 0) {
+    let h =
+      Math.pow(x * cos + y * sin, 2) / (4 * a * a) +
+      Math.pow(y * cos - x * sin, 2) / (4 * b * b);
+    if (h > 1) {
+      h = Math.sqrt(h);
+      a *= h;
+      b *= h;
+    }
+  }
+  const ellipse = [a * cos, a * sin, -b * sin, b * cos, 0, 0];
+  const m = multiplyTransformMatrices(transform, ellipse);
+  // Decompose the new ellipse matrix
+  const lastCol = m[2] * m[2] + m[3] * m[3];
+  const squareSum = m[0] * m[0] + m[1] * m[1] + lastCol;
+  const root =
+    Math.hypot(m[0] - m[3], m[1] + m[2]) * Math.hypot(m[0] + m[3], m[1] - m[2]);
+
+  if (!root) {
+    // circle
+    arc[0] = arc[1] = Math.sqrt(squareSum / 2);
+    arc[2] = 0;
+  } else {
+    const majorAxisSqr = (squareSum + root) / 2;
+    const minorAxisSqr = (squareSum - root) / 2;
+    const major = Math.abs(majorAxisSqr - lastCol) > 1e-6;
+    const sub = (major ? majorAxisSqr : minorAxisSqr) - lastCol;
+    const rowsSum = m[0] * m[2] + m[1] * m[3];
+    const term1 = m[0] * sub + m[2] * rowsSum;
+    const term2 = m[1] * sub + m[3] * rowsSum;
+    arc[0] = Math.sqrt(majorAxisSqr);
+    arc[1] = Math.sqrt(minorAxisSqr);
+    arc[2] =
+      (((major ? term2 < 0 : term1 > 0) ? -1 : 1) *
+        Math.acos((major ? term1 : term2) / Math.hypot(term1, term2)) *
+        180) /
+      Math.PI;
+  }
+
+  if (transform[0] < 0 !== transform[3] < 0) {
+    // Flip the sweep flag if coordinates are being flipped horizontally XOR vertically
+    arc[4] = 1 - arc[4];
+  }
+
+  return arc;
+};
+
+/**
+ * Multiply transformation matrices.
+ *
+ * @type {(a: number[], b: number[]) => number[]}
+ */
+const multiplyTransformMatrices = (a, b) => {
+  return [
+    a[0] * b[0] + a[2] * b[1],
+    a[1] * b[0] + a[3] * b[1],
+    a[0] * b[2] + a[2] * b[3],
+    a[1] * b[2] + a[3] * b[3],
+    a[0] * b[4] + a[2] * b[5] + a[4],
+    a[1] * b[4] + a[3] * b[5] + a[5],
+  ];
+};

backend/node_modules/svgo/plugins/addAttributesToSVGElement.js

@@ -0,0 +1,82 @@
+'use strict';
+
+exports.name = 'addAttributesToSVGElement';
+exports.description = 'adds attributes to an outer <svg> element';
+
+var ENOCLS = `Error in plugin "addAttributesToSVGElement": absent parameters.
+It should have a list of "attributes" or one "attribute".
+Config example:
+
+plugins: [
+  {
+    name: 'addAttributesToSVGElement',
+    params: {
+      attribute: "mySvg"
+    }
+  }
+]
+
+plugins: [
+  {
+    name: 'addAttributesToSVGElement',
+    params: {
+      attributes: ["mySvg", "size-big"]
+    }
+  }
+]
+
+plugins: [
+  {
+    name: 'addAttributesToSVGElement',
+    params: {
+      attributes: [
+        {
+          focusable: false
+        },
+        {
+          'data-image': icon
+        }
+      ]
+    }
+  }
+]
+`;
+
+/**
+ * Add attributes to an outer <svg> element. Example config:
+ *
+ * @author April Arcus
+ *
+ * @type {import('./plugins-types').Plugin<'addAttributesToSVGElement'>}
+ */
+exports.fn = (root, params) => {
+  if (!Array.isArray(params.attributes) && !params.attribute) {
+    console.error(ENOCLS);
+    return null;
+  }
+  const attributes = params.attributes || [params.attribute];
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        if (node.name === 'svg' && parentNode.type === 'root') {
+          for (const attribute of attributes) {
+            if (typeof attribute === 'string') {
+              if (node.attributes[attribute] == null) {
+                // @ts-ignore disallow explicit nullable attribute value
+                node.attributes[attribute] = undefined;
+              }
+            }
+            if (typeof attribute === 'object') {
+              for (const key of Object.keys(attribute)) {
+                if (node.attributes[key] == null) {
+                  // @ts-ignore disallow explicit nullable attribute value
+                  node.attributes[key] = attribute[key];
+                }
+              }
+            }
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/addClassesToSVGElement.js

@@ -0,0 +1,82 @@
+'use strict';
+
+exports.name = 'addClassesToSVGElement';
+exports.description = 'adds classnames to an outer <svg> element';
+
+var ENOCLS = `Error in plugin "addClassesToSVGElement": absent parameters.
+It should have a list of classes in "classNames" or one "className".
+Config example:
+
+plugins: [
+  {
+    name: "addClassesToSVGElement",
+    params: {
+      className: "mySvg"
+    }
+  }
+]
+
+plugins: [
+  {
+    name: "addClassesToSVGElement",
+    params: {
+      classNames: ["mySvg", "size-big"]
+    }
+  }
+]
+`;
+
+/**
+ * Add classnames to an outer <svg> element. Example config:
+ *
+ * plugins: [
+ *   {
+ *     name: "addClassesToSVGElement",
+ *     params: {
+ *       className: "mySvg"
+ *     }
+ *   }
+ * ]
+ *
+ * plugins: [
+ *   {
+ *     name: "addClassesToSVGElement",
+ *     params: {
+ *       classNames: ["mySvg", "size-big"]
+ *     }
+ *   }
+ * ]
+ *
+ * @author April Arcus
+ *
+ * @type {import('./plugins-types').Plugin<'addClassesToSVGElement'>}
+ */
+exports.fn = (root, params) => {
+  if (
+    !(Array.isArray(params.classNames) && params.classNames.some(String)) &&
+    !params.className
+  ) {
+    console.error(ENOCLS);
+    return null;
+  }
+  const classNames = params.classNames || [params.className];
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        if (node.name === 'svg' && parentNode.type === 'root') {
+          const classList = new Set(
+            node.attributes.class == null
+              ? null
+              : node.attributes.class.split(' '),
+          );
+          for (const className of classNames) {
+            if (className != null) {
+              classList.add(className);
+            }
+          }
+          node.attributes.class = Array.from(classList).join(' ');
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/applyTransforms.js

@@ -0,0 +1,388 @@
+'use strict';
+
+/**
+ * @typedef {import('../lib/types').PathDataItem} PathDataItem
+ * @typedef {import('../lib/types').XastElement} XastElement
+ */
+
+const { collectStylesheet, computeStyle } = require('../lib/style.js');
+const {
+  transformsMultiply,
+  transform2js,
+  transformArc,
+} = require('./_transforms.js');
+const { path2js } = require('./_path.js');
+const {
+  removeLeadingZero,
+  includesUrlReference,
+} = require('../lib/svgo/tools.js');
+const { referencesProps, attrsGroupsDefaults } = require('./_collections.js');
+
+/**
+ * @typedef {PathDataItem[]} PathData
+ * @typedef {number[]} Matrix
+ */
+
+const regNumericValues = /[-+]?(\d*\.\d+|\d+\.?)(?:[eE][-+]?\d+)?/g;
+
+/**
+ * Apply transformation(s) to the Path data.
+ *
+ * @type {import('../lib/types').Plugin<{
+ *   transformPrecision: number,
+ *   applyTransformsStroked: boolean,
+ * }>}
+ */
+const applyTransforms = (root, params) => {
+  const stylesheet = collectStylesheet(root);
+  return {
+    element: {
+      enter: (node) => {
+        if (node.attributes.d == null) {
+          return;
+        }
+
+        // stroke and stroke-width can be redefined with <use>
+        if (node.attributes.id != null) {
+          return;
+        }
+
+        // if there are no 'stroke' attr and references to other objects such as
+        // gradients or clip-path which are also subjects to transform.
+        if (
+          node.attributes.transform == null ||
+          node.attributes.transform === '' ||
+          // styles are not considered when applying transform
+          // can be fixed properly with new style engine
+          node.attributes.style != null ||
+          Object.entries(node.attributes).some(
+            ([name, value]) =>
+              referencesProps.has(name) && includesUrlReference(value),
+          )
+        ) {
+          return;
+        }
+
+        const computedStyle = computeStyle(stylesheet, node);
+        const transformStyle = computedStyle.transform;
+
+        // Transform overridden in <style> tag which is not considered
+        if (
+          transformStyle.type === 'static' &&
+          transformStyle.value !== node.attributes.transform
+        ) {
+          return;
+        }
+
+        const matrix = transformsMultiply(
+          transform2js(node.attributes.transform),
+        );
+
+        const stroke =
+          computedStyle.stroke?.type === 'static'
+            ? computedStyle.stroke.value
+            : null;
+
+        const strokeWidth =
+          computedStyle['stroke-width']?.type === 'static'
+            ? computedStyle['stroke-width'].value
+            : null;
+        const transformPrecision = params.transformPrecision;
+
+        if (
+          computedStyle.stroke?.type === 'dynamic' ||
+          computedStyle['stroke-width']?.type === 'dynamic'
+        ) {
+          return;
+        }
+
+        const scale = Number(
+          Math.sqrt(
+            matrix.data[0] * matrix.data[0] + matrix.data[1] * matrix.data[1],
+          ).toFixed(transformPrecision),
+        );
+
+        if (stroke && stroke != 'none') {
+          if (!params.applyTransformsStroked) {
+            return;
+          }
+
+          // stroke cannot be transformed with different vertical and horizontal scale or skew
+          if (
+            (matrix.data[0] !== matrix.data[3] ||
+              matrix.data[1] !== -matrix.data[2]) &&
+            (matrix.data[0] !== -matrix.data[3] ||
+              matrix.data[1] !== matrix.data[2])
+          ) {
+            return;
+          }
+
+          // apply transform to stroke-width, stroke-dashoffset and stroke-dasharray
+          if (scale !== 1) {
+            if (node.attributes['vector-effect'] !== 'non-scaling-stroke') {
+              node.attributes['stroke-width'] = (
+                strokeWidth || attrsGroupsDefaults.presentation['stroke-width']
+              )
+                .trim()
+                .replace(regNumericValues, (num) =>
+                  removeLeadingZero(Number(num) * scale),
+                );
+
+              if (node.attributes['stroke-dashoffset'] != null) {
+                node.attributes['stroke-dashoffset'] = node.attributes[
+                  'stroke-dashoffset'
+                ]
+                  .trim()
+                  .replace(regNumericValues, (num) =>
+                    removeLeadingZero(Number(num) * scale),
+                  );
+              }
+
+              if (node.attributes['stroke-dasharray'] != null) {
+                node.attributes['stroke-dasharray'] = node.attributes[
+                  'stroke-dasharray'
+                ]
+                  .trim()
+                  .replace(regNumericValues, (num) =>
+                    removeLeadingZero(Number(num) * scale),
+                  );
+              }
+            }
+          }
+        }
+
+        const pathData = path2js(node);
+        applyMatrixToPathData(pathData, matrix.data);
+
+        // remove transform attr
+        delete node.attributes.transform;
+      },
+    },
+  };
+};
+exports.applyTransforms = applyTransforms;
+
+/**
+ * @type {(matrix: Matrix, x: number, y: number) => [number, number]}
+ */
+const transformAbsolutePoint = (matrix, x, y) => {
+  const newX = matrix[0] * x + matrix[2] * y + matrix[4];
+  const newY = matrix[1] * x + matrix[3] * y + matrix[5];
+  return [newX, newY];
+};
+
+/**
+ * @type {(matrix: Matrix, x: number, y: number) => [number, number]}
+ */
+const transformRelativePoint = (matrix, x, y) => {
+  const newX = matrix[0] * x + matrix[2] * y;
+  const newY = matrix[1] * x + matrix[3] * y;
+  return [newX, newY];
+};
+
+/**
+ * @type {(pathData: PathData, matrix: Matrix) => void}
+ */
+const applyMatrixToPathData = (pathData, matrix) => {
+  /**
+   * @type {[number, number]}
+   */
+  const start = [0, 0];
+  /**
+   * @type {[number, number]}
+   */
+  const cursor = [0, 0];
+
+  for (const pathItem of pathData) {
+    let { command, args } = pathItem;
+
+    // moveto (x y)
+    if (command === 'M') {
+      cursor[0] = args[0];
+      cursor[1] = args[1];
+      start[0] = cursor[0];
+      start[1] = cursor[1];
+      const [x, y] = transformAbsolutePoint(matrix, args[0], args[1]);
+      args[0] = x;
+      args[1] = y;
+    }
+    if (command === 'm') {
+      cursor[0] += args[0];
+      cursor[1] += args[1];
+      start[0] = cursor[0];
+      start[1] = cursor[1];
+      const [x, y] = transformRelativePoint(matrix, args[0], args[1]);
+      args[0] = x;
+      args[1] = y;
+    }
+
+    // horizontal lineto (x)
+    // convert to lineto to handle two-dimentional transforms
+    if (command === 'H') {
+      command = 'L';
+      args = [args[0], cursor[1]];
+    }
+    if (command === 'h') {
+      command = 'l';
+      args = [args[0], 0];
+    }
+
+    // vertical lineto (y)
+    // convert to lineto to handle two-dimentional transforms
+    if (command === 'V') {
+      command = 'L';
+      args = [cursor[0], args[0]];
+    }
+    if (command === 'v') {
+      command = 'l';
+      args = [0, args[0]];
+    }
+
+    // lineto (x y)
+    if (command === 'L') {
+      cursor[0] = args[0];
+      cursor[1] = args[1];
+      const [x, y] = transformAbsolutePoint(matrix, args[0], args[1]);
+      args[0] = x;
+      args[1] = y;
+    }
+    if (command === 'l') {
+      cursor[0] += args[0];
+      cursor[1] += args[1];
+      const [x, y] = transformRelativePoint(matrix, args[0], args[1]);
+      args[0] = x;
+      args[1] = y;
+    }
+
+    // curveto (x1 y1 x2 y2 x y)
+    if (command === 'C') {
+      cursor[0] = args[4];
+      cursor[1] = args[5];
+      const [x1, y1] = transformAbsolutePoint(matrix, args[0], args[1]);
+      const [x2, y2] = transformAbsolutePoint(matrix, args[2], args[3]);
+      const [x, y] = transformAbsolutePoint(matrix, args[4], args[5]);
+      args[0] = x1;
+      args[1] = y1;
+      args[2] = x2;
+      args[3] = y2;
+      args[4] = x;
+      args[5] = y;
+    }
+    if (command === 'c') {
+      cursor[0] += args[4];
+      cursor[1] += args[5];
+      const [x1, y1] = transformRelativePoint(matrix, args[0], args[1]);
+      const [x2, y2] = transformRelativePoint(matrix, args[2], args[3]);
+      const [x, y] = transformRelativePoint(matrix, args[4], args[5]);
+      args[0] = x1;
+      args[1] = y1;
+      args[2] = x2;
+      args[3] = y2;
+      args[4] = x;
+      args[5] = y;
+    }
+
+    // smooth curveto (x2 y2 x y)
+    if (command === 'S') {
+      cursor[0] = args[2];
+      cursor[1] = args[3];
+      const [x2, y2] = transformAbsolutePoint(matrix, args[0], args[1]);
+      const [x, y] = transformAbsolutePoint(matrix, args[2], args[3]);
+      args[0] = x2;
+      args[1] = y2;
+      args[2] = x;
+      args[3] = y;
+    }
+    if (command === 's') {
+      cursor[0] += args[2];
+      cursor[1] += args[3];
+      const [x2, y2] = transformRelativePoint(matrix, args[0], args[1]);
+      const [x, y] = transformRelativePoint(matrix, args[2], args[3]);
+      args[0] = x2;
+      args[1] = y2;
+      args[2] = x;
+      args[3] = y;
+    }
+
+    // quadratic Bézier curveto (x1 y1 x y)
+    if (command === 'Q') {
+      cursor[0] = args[2];
+      cursor[1] = args[3];
+      const [x1, y1] = transformAbsolutePoint(matrix, args[0], args[1]);
+      const [x, y] = transformAbsolutePoint(matrix, args[2], args[3]);
+      args[0] = x1;
+      args[1] = y1;
+      args[2] = x;
+      args[3] = y;
+    }
+    if (command === 'q') {
+      cursor[0] += args[2];
+      cursor[1] += args[3];
+      const [x1, y1] = transformRelativePoint(matrix, args[0], args[1]);
+      const [x, y] = transformRelativePoint(matrix, args[2], args[3]);
+      args[0] = x1;
+      args[1] = y1;
+      args[2] = x;
+      args[3] = y;
+    }
+
+    // smooth quadratic Bézier curveto (x y)
+    if (command === 'T') {
+      cursor[0] = args[0];
+      cursor[1] = args[1];
+      const [x, y] = transformAbsolutePoint(matrix, args[0], args[1]);
+      args[0] = x;
+      args[1] = y;
+    }
+    if (command === 't') {
+      cursor[0] += args[0];
+      cursor[1] += args[1];
+      const [x, y] = transformRelativePoint(matrix, args[0], args[1]);
+      args[0] = x;
+      args[1] = y;
+    }
+
+    // elliptical arc (rx ry x-axis-rotation large-arc-flag sweep-flag x y)
+    if (command === 'A') {
+      transformArc(cursor, args, matrix);
+      cursor[0] = args[5];
+      cursor[1] = args[6];
+      // reduce number of digits in rotation angle
+      if (Math.abs(args[2]) > 80) {
+        const a = args[0];
+        const rotation = args[2];
+        args[0] = args[1];
+        args[1] = a;
+        args[2] = rotation + (rotation > 0 ? -90 : 90);
+      }
+      const [x, y] = transformAbsolutePoint(matrix, args[5], args[6]);
+      args[5] = x;
+      args[6] = y;
+    }
+    if (command === 'a') {
+      transformArc([0, 0], args, matrix);
+      cursor[0] += args[5];
+      cursor[1] += args[6];
+      // reduce number of digits in rotation angle
+      if (Math.abs(args[2]) > 80) {
+        const a = args[0];
+        const rotation = args[2];
+        args[0] = args[1];
+        args[1] = a;
+        args[2] = rotation + (rotation > 0 ? -90 : 90);
+      }
+      const [x, y] = transformRelativePoint(matrix, args[5], args[6]);
+      args[5] = x;
+      args[6] = y;
+    }
+
+    // closepath
+    if (command === 'z' || command === 'Z') {
+      cursor[0] = start[0];
+      cursor[1] = start[1];
+    }
+
+    pathItem.command = command;
+    pathItem.args = args;
+  }
+};

backend/node_modules/svgo/plugins/cleanupAttrs.js

@@ -0,0 +1,49 @@
+'use strict';
+
+exports.name = 'cleanupAttrs';
+exports.description =
+  'cleanups attributes from newlines, trailing and repeating spaces';
+
+const regNewlinesNeedSpace = /(\S)\r?\n(\S)/g;
+const regNewlines = /\r?\n/g;
+const regSpaces = /\s{2,}/g;
+
+/**
+ * Cleanup attributes values from newlines, trailing and repeating spaces.
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'cleanupAttrs'>}
+ */
+exports.fn = (root, params) => {
+  const { newlines = true, trim = true, spaces = true } = params;
+  return {
+    element: {
+      enter: (node) => {
+        for (const name of Object.keys(node.attributes)) {
+          if (newlines) {
+            // new line which requires a space instead of themself
+            node.attributes[name] = node.attributes[name].replace(
+              regNewlinesNeedSpace,
+              (match, p1, p2) => p1 + ' ' + p2,
+            );
+            // simple new line
+            node.attributes[name] = node.attributes[name].replace(
+              regNewlines,
+              '',
+            );
+          }
+          if (trim) {
+            node.attributes[name] = node.attributes[name].trim();
+          }
+          if (spaces) {
+            node.attributes[name] = node.attributes[name].replace(
+              regSpaces,
+              ' ',
+            );
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/cleanupEnableBackground.js

@@ -0,0 +1,165 @@
+'use strict';
+
+const csstree = require('css-tree');
+const { visit } = require('../lib/xast.js');
+
+exports.name = 'cleanupEnableBackground';
+exports.description =
+  'remove or cleanup enable-background attribute when possible';
+
+const regEnableBackground =
+  /^new\s0\s0\s([-+]?\d*\.?\d+([eE][-+]?\d+)?)\s([-+]?\d*\.?\d+([eE][-+]?\d+)?)$/;
+
+/**
+ * Remove or cleanup enable-background attr which coincides with a width/height box.
+ *
+ * @see https://www.w3.org/TR/SVG11/filters.html#EnableBackgroundProperty
+ * @example
+ * <svg width="100" height="50" enable-background="new 0 0 100 50">
+ *             ⬇
+ * <svg width="100" height="50">
+ * @author Kir Belevich
+ * @type {import('./plugins-types').Plugin<'cleanupEnableBackground'>}
+ */
+exports.fn = (root) => {
+  let hasFilter = false;
+
+  visit(root, {
+    element: {
+      enter: (node) => {
+        if (node.name === 'filter') {
+          hasFilter = true;
+        }
+      },
+    },
+  });
+
+  return {
+    element: {
+      enter: (node) => {
+        /** @type {?csstree.CssNode} */
+        let newStyle = null;
+        /** @type {?csstree.ListItem<csstree.CssNode>} */
+        let enableBackgroundDeclaration = null;
+
+        if (node.attributes.style != null) {
+          newStyle = csstree.parse(node.attributes.style, {
+            context: 'declarationList',
+          });
+
+          if (newStyle.type === 'DeclarationList') {
+            /** @type {csstree.ListItem<csstree.CssNode>[]} */
+            const enableBackgroundDeclarations = [];
+
+            csstree.walk(newStyle, (node, nodeItem) => {
+              if (
+                node.type === 'Declaration' &&
+                node.property === 'enable-background'
+              ) {
+                enableBackgroundDeclarations.push(nodeItem);
+                enableBackgroundDeclaration = nodeItem;
+              }
+            });
+
+            for (let i = 0; i < enableBackgroundDeclarations.length - 1; i++) {
+              newStyle.children.remove(enableBackgroundDeclarations[i]);
+            }
+          }
+        }
+
+        if (!hasFilter) {
+          delete node.attributes['enable-background'];
+
+          if (newStyle?.type === 'DeclarationList') {
+            if (enableBackgroundDeclaration) {
+              newStyle.children.remove(enableBackgroundDeclaration);
+            }
+
+            if (newStyle.children.isEmpty) {
+              delete node.attributes.style;
+            } else {
+              node.attributes.style = csstree.generate(newStyle);
+            }
+          }
+
+          return;
+        }
+
+        const hasDimensions =
+          node.attributes.width != null && node.attributes.height != null;
+
+        if (
+          (node.name === 'svg' ||
+            node.name === 'mask' ||
+            node.name === 'pattern') &&
+          hasDimensions
+        ) {
+          const attrValue = node.attributes['enable-background'];
+          const attrCleaned = cleanupValue(
+            attrValue,
+            node.name,
+            node.attributes.width,
+            node.attributes.height,
+          );
+
+          if (attrCleaned) {
+            node.attributes['enable-background'] = attrCleaned;
+          } else {
+            delete node.attributes['enable-background'];
+          }
+
+          if (
+            newStyle?.type === 'DeclarationList' &&
+            enableBackgroundDeclaration
+          ) {
+            const styleValue = csstree.generate(
+              // @ts-ignore
+              enableBackgroundDeclaration.data.value,
+            );
+            const styleCleaned = cleanupValue(
+              styleValue,
+              node.name,
+              node.attributes.width,
+              node.attributes.height,
+            );
+
+            if (styleCleaned) {
+              // @ts-ignore
+              enableBackgroundDeclaration.data.value = {
+                type: 'Raw',
+                value: styleCleaned,
+              };
+            } else {
+              newStyle.children.remove(enableBackgroundDeclaration);
+            }
+          }
+        }
+
+        if (newStyle?.type === 'DeclarationList') {
+          if (newStyle.children.isEmpty) {
+            delete node.attributes.style;
+          } else {
+            node.attributes.style = csstree.generate(newStyle);
+          }
+        }
+      },
+    },
+  };
+};
+
+/**
+ * @param {string} value Value of a enable-background attribute or style declaration.
+ * @param {string} nodeName Name of the node the value was assigned to.
+ * @param {string} width Width of the node the value was assigned to.
+ * @param {string} height Height of the node the value was assigned to.
+ * @returns {string | undefined} Cleaned up value, or undefined if it's redundant.
+ */
+const cleanupValue = (value, nodeName, width, height) => {
+  const match = regEnableBackground.exec(value);
+
+  if (match != null && width === match[1] && height === match[3]) {
+    return nodeName === 'svg' ? undefined : 'new';
+  }
+
+  return value;
+};

backend/node_modules/svgo/plugins/cleanupIds.js

@@ -0,0 +1,265 @@
+'use strict';
+
+/**
+ * @typedef {import('../lib/types').XastElement} XastElement
+ */
+
+const { visitSkip } = require('../lib/xast.js');
+const { hasScripts, findReferences } = require('../lib/svgo/tools');
+
+exports.name = 'cleanupIds';
+exports.description = 'removes unused IDs and minifies used';
+
+const generateIdChars = [
+  'a',
+  'b',
+  'c',
+  'd',
+  'e',
+  'f',
+  'g',
+  'h',
+  'i',
+  'j',
+  'k',
+  'l',
+  'm',
+  'n',
+  'o',
+  'p',
+  'q',
+  'r',
+  's',
+  't',
+  'u',
+  'v',
+  'w',
+  'x',
+  'y',
+  'z',
+  'A',
+  'B',
+  'C',
+  'D',
+  'E',
+  'F',
+  'G',
+  'H',
+  'I',
+  'J',
+  'K',
+  'L',
+  'M',
+  'N',
+  'O',
+  'P',
+  'Q',
+  'R',
+  'S',
+  'T',
+  'U',
+  'V',
+  'W',
+  'X',
+  'Y',
+  'Z',
+];
+const maxIdIndex = generateIdChars.length - 1;
+
+/**
+ * Check if an ID starts with any one of a list of strings.
+ *
+ * @type {(string: string, prefixes: string[]) => boolean}
+ */
+const hasStringPrefix = (string, prefixes) => {
+  for (const prefix of prefixes) {
+    if (string.startsWith(prefix)) {
+      return true;
+    }
+  }
+  return false;
+};
+
+/**
+ * Generate unique minimal ID.
+ *
+ * @param {?number[]} currentId
+ * @returns {number[]}
+ */
+const generateId = (currentId) => {
+  if (currentId == null) {
+    return [0];
+  }
+  currentId[currentId.length - 1] += 1;
+  for (let i = currentId.length - 1; i > 0; i--) {
+    if (currentId[i] > maxIdIndex) {
+      currentId[i] = 0;
+      if (currentId[i - 1] !== undefined) {
+        currentId[i - 1]++;
+      }
+    }
+  }
+  if (currentId[0] > maxIdIndex) {
+    currentId[0] = 0;
+    currentId.unshift(0);
+  }
+  return currentId;
+};
+
+/**
+ * Get string from generated ID array.
+ *
+ * @type {(arr: number[]) => string}
+ */
+const getIdString = (arr) => {
+  return arr.map((i) => generateIdChars[i]).join('');
+};
+
+/**
+ * Remove unused and minify used IDs
+ * (only if there are no any <style> or <script>).
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'cleanupIds'>}
+ */
+exports.fn = (_root, params) => {
+  const {
+    remove = true,
+    minify = true,
+    preserve = [],
+    preservePrefixes = [],
+    force = false,
+  } = params;
+  const preserveIds = new Set(
+    Array.isArray(preserve) ? preserve : preserve ? [preserve] : [],
+  );
+  const preserveIdPrefixes = Array.isArray(preservePrefixes)
+    ? preservePrefixes
+    : preservePrefixes
+      ? [preservePrefixes]
+      : [];
+  /**
+   * @type {Map<string, XastElement>}
+   */
+  const nodeById = new Map();
+  /**
+   * @type {Map<string, {element: XastElement, name: string }[]>}
+   */
+  const referencesById = new Map();
+  let deoptimized = false;
+
+  return {
+    element: {
+      enter: (node) => {
+        if (!force) {
+          // deoptimize if style or scripts are present
+          if (
+            (node.name === 'style' && node.children.length !== 0) ||
+            hasScripts(node)
+          ) {
+            deoptimized = true;
+            return;
+          }
+
+          // avoid removing IDs if the whole SVG consists only of defs
+          if (node.name === 'svg') {
+            let hasDefsOnly = true;
+            for (const child of node.children) {
+              if (child.type !== 'element' || child.name !== 'defs') {
+                hasDefsOnly = false;
+                break;
+              }
+            }
+            if (hasDefsOnly) {
+              return visitSkip;
+            }
+          }
+        }
+
+        for (const [name, value] of Object.entries(node.attributes)) {
+          if (name === 'id') {
+            // collect all ids
+            const id = value;
+            if (nodeById.has(id)) {
+              delete node.attributes.id; // remove repeated id
+            } else {
+              nodeById.set(id, node);
+            }
+          } else {
+            const ids = findReferences(name, value);
+            for (const id of ids) {
+              let refs = referencesById.get(id);
+              if (refs == null) {
+                refs = [];
+                referencesById.set(id, refs);
+              }
+              refs.push({ element: node, name });
+            }
+          }
+        }
+      },
+    },
+
+    root: {
+      exit: () => {
+        if (deoptimized) {
+          return;
+        }
+        /**
+         * @param {string} id
+         * @returns {boolean}
+         */
+        const isIdPreserved = (id) =>
+          preserveIds.has(id) || hasStringPrefix(id, preserveIdPrefixes);
+        /** @type {?number[]} */
+        let currentId = null;
+        for (const [id, refs] of referencesById) {
+          const node = nodeById.get(id);
+          if (node != null) {
+            // replace referenced IDs with the minified ones
+            if (minify && isIdPreserved(id) === false) {
+              /** @type {?string} */
+              let currentIdString = null;
+              do {
+                currentId = generateId(currentId);
+                currentIdString = getIdString(currentId);
+              } while (
+                isIdPreserved(currentIdString) ||
+                (referencesById.has(currentIdString) &&
+                  nodeById.get(currentIdString) == null)
+              );
+              node.attributes.id = currentIdString;
+              for (const { element, name } of refs) {
+                const value = element.attributes[name];
+                if (value.includes('#')) {
+                  // replace id in href and url()
+                  element.attributes[name] = value.replace(
+                    `#${encodeURI(id)}`,
+                    `#${currentIdString}`,
+                  );
+                } else {
+                  // replace id in begin attribute
+                  element.attributes[name] = value.replace(
+                    `${id}.`,
+                    `${currentIdString}.`,
+                  );
+                }
+              }
+            }
+            // keep referenced node
+            nodeById.delete(id);
+          }
+        }
+        // remove non-referenced IDs attributes from elements
+        if (remove) {
+          for (const [id, node] of nodeById) {
+            if (isIdPreserved(id) === false) {
+              delete node.attributes.id;
+            }
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/cleanupListOfValues.js

@@ -0,0 +1,147 @@
+'use strict';
+
+const { removeLeadingZero } = require('../lib/svgo/tools.js');
+
+exports.name = 'cleanupListOfValues';
+exports.description = 'rounds list of values to the fixed precision';
+
+const regNumericValues =
+  /^([-+]?\d*\.?\d+([eE][-+]?\d+)?)(px|pt|pc|mm|cm|m|in|ft|em|ex|%)?$/;
+const regSeparator = /\s+,?\s*|,\s*/;
+const absoluteLengths = {
+  // relative to px
+  cm: 96 / 2.54,
+  mm: 96 / 25.4,
+  in: 96,
+  pt: 4 / 3,
+  pc: 16,
+  px: 1,
+};
+
+/**
+ * Round list of values to the fixed precision.
+ *
+ * @example
+ * <svg viewBox="0 0 200.28423 200.28423" enable-background="new 0 0 200.28423 200.28423">
+ *         ⬇
+ * <svg viewBox="0 0 200.284 200.284" enable-background="new 0 0 200.284 200.284">
+ *
+ * <polygon points="208.250977 77.1308594 223.069336 ... "/>
+ *         ⬇
+ * <polygon points="208.251 77.131 223.069 ... "/>
+ *
+ * @author kiyopikko
+ *
+ * @type {import('./plugins-types').Plugin<'cleanupListOfValues'>}
+ */
+exports.fn = (_root, params) => {
+  const {
+    floatPrecision = 3,
+    leadingZero = true,
+    defaultPx = true,
+    convertToPx = true,
+  } = params;
+
+  /**
+   * @type {(lists: string) => string}
+   */
+  const roundValues = (lists) => {
+    const roundedList = [];
+
+    for (const elem of lists.split(regSeparator)) {
+      const match = elem.match(regNumericValues);
+      const matchNew = elem.match(/new/);
+
+      // if attribute value matches regNumericValues
+      if (match) {
+        // round it to the fixed precision
+        let num = Number(Number(match[1]).toFixed(floatPrecision));
+        /**
+         * @type {any}
+         */
+        let matchedUnit = match[3] || '';
+        /**
+         * @type{'' | keyof typeof absoluteLengths}
+         */
+        let units = matchedUnit;
+
+        // convert absolute values to pixels
+        if (convertToPx && units && units in absoluteLengths) {
+          const pxNum = Number(
+            (absoluteLengths[units] * Number(match[1])).toFixed(floatPrecision),
+          );
+
+          if (pxNum.toString().length < match[0].length) {
+            num = pxNum;
+            units = 'px';
+          }
+        }
+
+        // and remove leading zero
+        let str;
+        if (leadingZero) {
+          str = removeLeadingZero(num);
+        } else {
+          str = num.toString();
+        }
+
+        // remove default 'px' units
+        if (defaultPx && units === 'px') {
+          units = '';
+        }
+
+        roundedList.push(str + units);
+      }
+      // if attribute value is "new"(only enable-background).
+      else if (matchNew) {
+        roundedList.push('new');
+      } else if (elem) {
+        roundedList.push(elem);
+      }
+    }
+
+    return roundedList.join(' ');
+  };
+
+  return {
+    element: {
+      enter: (node) => {
+        if (node.attributes.points != null) {
+          node.attributes.points = roundValues(node.attributes.points);
+        }
+
+        if (node.attributes['enable-background'] != null) {
+          node.attributes['enable-background'] = roundValues(
+            node.attributes['enable-background'],
+          );
+        }
+
+        if (node.attributes.viewBox != null) {
+          node.attributes.viewBox = roundValues(node.attributes.viewBox);
+        }
+
+        if (node.attributes['stroke-dasharray'] != null) {
+          node.attributes['stroke-dasharray'] = roundValues(
+            node.attributes['stroke-dasharray'],
+          );
+        }
+
+        if (node.attributes.dx != null) {
+          node.attributes.dx = roundValues(node.attributes.dx);
+        }
+
+        if (node.attributes.dy != null) {
+          node.attributes.dy = roundValues(node.attributes.dy);
+        }
+
+        if (node.attributes.x != null) {
+          node.attributes.x = roundValues(node.attributes.x);
+        }
+
+        if (node.attributes.y != null) {
+          node.attributes.y = roundValues(node.attributes.y);
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/cleanupNumericValues.js

@@ -0,0 +1,106 @@
+'use strict';
+
+const { removeLeadingZero } = require('../lib/svgo/tools');
+
+exports.name = 'cleanupNumericValues';
+exports.description =
+  'rounds numeric values to the fixed precision, removes default ‘px’ units';
+
+const regNumericValues =
+  /^([-+]?\d*\.?\d+([eE][-+]?\d+)?)(px|pt|pc|mm|cm|m|in|ft|em|ex|%)?$/;
+
+const absoluteLengths = {
+  // relative to px
+  cm: 96 / 2.54,
+  mm: 96 / 25.4,
+  in: 96,
+  pt: 4 / 3,
+  pc: 16,
+  px: 1,
+};
+
+/**
+ * Round numeric values to the fixed precision,
+ * remove default 'px' units.
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'cleanupNumericValues'>}
+ */
+exports.fn = (_root, params) => {
+  const {
+    floatPrecision = 3,
+    leadingZero = true,
+    defaultPx = true,
+    convertToPx = true,
+  } = params;
+
+  return {
+    element: {
+      enter: (node) => {
+        if (node.attributes.viewBox != null) {
+          const nums = node.attributes.viewBox.split(/\s,?\s*|,\s*/g);
+          node.attributes.viewBox = nums
+            .map((value) => {
+              const num = Number(value);
+              return Number.isNaN(num)
+                ? value
+                : Number(num.toFixed(floatPrecision));
+            })
+            .join(' ');
+        }
+
+        for (const [name, value] of Object.entries(node.attributes)) {
+          // The `version` attribute is a text string and cannot be rounded
+          if (name === 'version') {
+            continue;
+          }
+
+          const match = value.match(regNumericValues);
+
+          // if attribute value matches regNumericValues
+          if (match) {
+            // round it to the fixed precision
+            let num = Number(Number(match[1]).toFixed(floatPrecision));
+            /**
+             * @type {any}
+             */
+            let matchedUnit = match[3] || '';
+            /**
+             * @type{'' | keyof typeof absoluteLengths}
+             */
+            let units = matchedUnit;
+
+            // convert absolute values to pixels
+            if (convertToPx && units !== '' && units in absoluteLengths) {
+              const pxNum = Number(
+                (absoluteLengths[units] * Number(match[1])).toFixed(
+                  floatPrecision,
+                ),
+              );
+              if (pxNum.toString().length < match[0].length) {
+                num = pxNum;
+                units = 'px';
+              }
+            }
+
+            // and remove leading zero
+            let str;
+            if (leadingZero) {
+              str = removeLeadingZero(num);
+            } else {
+              str = num.toString();
+            }
+
+            // remove default 'px' units
+            if (defaultPx && units === 'px') {
+              units = '';
+            }
+
+            node.attributes[name] = str + units;
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/collapseGroups.js

@@ -0,0 +1,134 @@
+'use strict';
+
+/**
+ * @typedef {import('../lib/types').XastNode} XastNode
+ */
+
+const { inheritableAttrs, elemsGroups } = require('./_collections.js');
+
+exports.name = 'collapseGroups';
+exports.description = 'collapses useless groups';
+
+/**
+ * @type {(node: XastNode, name: string) => boolean}
+ */
+const hasAnimatedAttr = (node, name) => {
+  if (node.type === 'element') {
+    if (
+      elemsGroups.animation.has(node.name) &&
+      node.attributes.attributeName === name
+    ) {
+      return true;
+    }
+    for (const child of node.children) {
+      if (hasAnimatedAttr(child, name)) {
+        return true;
+      }
+    }
+  }
+  return false;
+};
+
+/**
+ * Collapse useless groups.
+ *
+ * @example
+ * <g>
+ *     <g attr1="val1">
+ *         <path d="..."/>
+ *     </g>
+ * </g>
+ *         ⬇
+ * <g>
+ *     <g>
+ *         <path attr1="val1" d="..."/>
+ *     </g>
+ * </g>
+ *         ⬇
+ * <path attr1="val1" d="..."/>
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'collapseGroups'>}
+ */
+exports.fn = () => {
+  return {
+    element: {
+      exit: (node, parentNode) => {
+        if (parentNode.type === 'root' || parentNode.name === 'switch') {
+          return;
+        }
+        // non-empty groups
+        if (node.name !== 'g' || node.children.length === 0) {
+          return;
+        }
+
+        // move group attributes to the single child element
+        if (
+          Object.keys(node.attributes).length !== 0 &&
+          node.children.length === 1
+        ) {
+          const firstChild = node.children[0];
+          // TODO untangle this mess
+          if (
+            firstChild.type === 'element' &&
+            firstChild.attributes.id == null &&
+            node.attributes.filter == null &&
+            (node.attributes.class == null ||
+              firstChild.attributes.class == null) &&
+            ((node.attributes['clip-path'] == null &&
+              node.attributes.mask == null) ||
+              (firstChild.name === 'g' &&
+                node.attributes.transform == null &&
+                firstChild.attributes.transform == null))
+          ) {
+            for (const [name, value] of Object.entries(node.attributes)) {
+              // avoid copying to not conflict with animated attribute
+              if (hasAnimatedAttr(firstChild, name)) {
+                return;
+              }
+              if (firstChild.attributes[name] == null) {
+                firstChild.attributes[name] = value;
+              } else if (name === 'transform') {
+                firstChild.attributes[name] =
+                  value + ' ' + firstChild.attributes[name];
+              } else if (firstChild.attributes[name] === 'inherit') {
+                firstChild.attributes[name] = value;
+              } else if (
+                inheritableAttrs.has(name) === false &&
+                firstChild.attributes[name] !== value
+              ) {
+                return;
+              }
+              delete node.attributes[name];
+            }
+          }
+        }
+
+        // collapse groups without attributes
+        if (Object.keys(node.attributes).length === 0) {
+          // animation elements "add" attributes to group
+          // group should be preserved
+          for (const child of node.children) {
+            if (
+              child.type === 'element' &&
+              elemsGroups.animation.has(child.name)
+            ) {
+              return;
+            }
+          }
+          // replace current node with all its children
+          const index = parentNode.children.indexOf(node);
+          parentNode.children.splice(index, 1, ...node.children);
+          // TODO remove legacy parentNode in v4
+          for (const child of node.children) {
+            Object.defineProperty(child, 'parentNode', {
+              writable: true,
+              value: parentNode,
+            });
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/convertColors.js

@@ -0,0 +1,144 @@
+'use strict';
+
+const collections = require('./_collections.js');
+
+exports.name = 'convertColors';
+exports.description = 'converts colors: rgb() to #rrggbb and #rrggbb to #rgb';
+
+const rNumber = '([+-]?(?:\\d*\\.\\d+|\\d+\\.?)%?)';
+const rComma = '\\s*,\\s*';
+const regRGB = new RegExp(
+  '^rgb\\(\\s*' + rNumber + rComma + rNumber + rComma + rNumber + '\\s*\\)$',
+);
+const regHEX = /^#(([a-fA-F0-9])\2){3}$/;
+
+/**
+ * Convert [r, g, b] to #rrggbb.
+ *
+ * @see https://gist.github.com/983535
+ *
+ * @example
+ * rgb2hex([255, 255, 255]) // '#ffffff'
+ *
+ * @author Jed Schmidt
+ *
+ * @type {(rgb: number[]) => string}
+ */
+const convertRgbToHex = ([r, g, b]) => {
+  // combine the octets into a 32-bit integer as: [1][r][g][b]
+  const hexNumber =
+    // operator precedence is (+) > (<<) > (|)
+    ((((256 + // [1][0]
+      r) << // [1][r]
+      8) | // [1][r][0]
+      g) << // [1][r][g]
+      8) | // [1][r][g][0]
+    b;
+  // serialize [1][r][g][b] to a hex string, and
+  // remove the 1 to get the number with 0s intact
+  return '#' + hexNumber.toString(16).slice(1).toUpperCase();
+};
+
+/**
+ * Convert different colors formats in element attributes to hex.
+ *
+ * @see https://www.w3.org/TR/SVG11/types.html#DataTypeColor
+ * @see https://www.w3.org/TR/SVG11/single-page.html#types-ColorKeywords
+ *
+ * @example
+ * Convert color name keyword to long hex:
+ * fuchsia ➡ #ff00ff
+ *
+ * Convert rgb() to long hex:
+ * rgb(255, 0, 255) ➡ #ff00ff
+ * rgb(50%, 100, 100%) ➡ #7f64ff
+ *
+ * Convert long hex to short hex:
+ * #aabbcc ➡ #abc
+ *
+ * Convert hex to short name
+ * #000080 ➡ navy
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'convertColors'>}
+ */
+exports.fn = (_root, params) => {
+  const {
+    currentColor = false,
+    names2hex = true,
+    rgb2hex = true,
+    shorthex = true,
+    shortname = true,
+  } = params;
+
+  return {
+    element: {
+      enter: (node) => {
+        for (const [name, value] of Object.entries(node.attributes)) {
+          if (collections.colorsProps.has(name)) {
+            let val = value;
+
+            // convert colors to currentColor
+            if (currentColor) {
+              let matched;
+              if (typeof currentColor === 'string') {
+                matched = val === currentColor;
+              } else if (currentColor instanceof RegExp) {
+                matched = currentColor.exec(val) != null;
+              } else {
+                matched = val !== 'none';
+              }
+              if (matched) {
+                val = 'currentColor';
+              }
+            }
+
+            // convert color name keyword to long hex
+            if (names2hex) {
+              const colorName = val.toLowerCase();
+              if (collections.colorsNames[colorName] != null) {
+                val = collections.colorsNames[colorName];
+              }
+            }
+
+            // convert rgb() to long hex
+            if (rgb2hex) {
+              let match = val.match(regRGB);
+              if (match != null) {
+                let nums = match.slice(1, 4).map((m) => {
+                  let n;
+                  if (m.indexOf('%') > -1) {
+                    n = Math.round(parseFloat(m) * 2.55);
+                  } else {
+                    n = Number(m);
+                  }
+                  return Math.max(0, Math.min(n, 255));
+                });
+                val = convertRgbToHex(nums);
+              }
+            }
+
+            // convert long hex to short hex
+            if (shorthex) {
+              let match = val.match(regHEX);
+              if (match != null) {
+                val = '#' + match[0][1] + match[0][3] + match[0][5];
+              }
+            }
+
+            // convert hex to short name
+            if (shortname) {
+              const colorName = val.toLowerCase();
+              if (collections.colorsShortNames[colorName] != null) {
+                val = collections.colorsShortNames[colorName];
+              }
+            }
+
+            node.attributes[name] = val;
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/convertEllipseToCircle.js

@@ -0,0 +1,37 @@
+'use strict';
+
+exports.name = 'convertEllipseToCircle';
+exports.description = 'converts non-eccentric <ellipse>s to <circle>s';
+
+/**
+ * Converts non-eccentric <ellipse>s to <circle>s.
+ *
+ * @see https://www.w3.org/TR/SVG11/shapes.html
+ *
+ * @author Taylor Hunt
+ *
+ * @type {import('./plugins-types').Plugin<'convertEllipseToCircle'>}
+ */
+exports.fn = () => {
+  return {
+    element: {
+      enter: (node) => {
+        if (node.name === 'ellipse') {
+          const rx = node.attributes.rx || '0';
+          const ry = node.attributes.ry || '0';
+          if (
+            rx === ry ||
+            rx === 'auto' ||
+            ry === 'auto' // SVG2
+          ) {
+            node.name = 'circle';
+            const radius = rx === 'auto' ? ry : rx;
+            delete node.attributes.rx;
+            delete node.attributes.ry;
+            node.attributes.r = radius;
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/convertOneStopGradients.js

@@ -0,0 +1,168 @@
+'use strict';
+
+/**
+ * @typedef {import('../lib/types').XastElement} XastElement
+ * @typedef {import('../lib/types').XastParent} XastParent
+ */
+
+const { attrsGroupsDefaults, colorsProps } = require('./_collections');
+const {
+  detachNodeFromParent,
+  querySelectorAll,
+  querySelector,
+} = require('../lib/xast');
+const { computeStyle, collectStylesheet } = require('../lib/style');
+
+exports.name = 'convertOneStopGradients';
+exports.description =
+  'converts one-stop (single color) gradients to a plain color';
+
+/**
+ * Converts one-stop (single color) gradients to a plain color.
+ *
+ * @author Seth Falco <seth@falco.fun>
+ * @type {import('./plugins-types').Plugin<'convertOneStopGradients'>}
+ * @see https://developer.mozilla.org/docs/Web/SVG/Element/linearGradient
+ * @see https://developer.mozilla.org/docs/Web/SVG/Element/radialGradient
+ */
+exports.fn = (root) => {
+  const stylesheet = collectStylesheet(root);
+
+  /**
+   * Parent defs that had gradients elements removed from them.
+   *
+   * @type {Set<XastElement>}
+   */
+  const effectedDefs = new Set();
+
+  /**
+   * @type {Map<XastElement, XastParent>}
+   */
+  const allDefs = new Map();
+
+  /**
+   * @type {Map<XastElement, XastParent>}
+   */
+  const gradientsToDetach = new Map();
+
+  /** Number of references to the xlink:href attribute. */
+  let xlinkHrefCount = 0;
+
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        if (node.attributes['xlink:href'] != null) {
+          xlinkHrefCount++;
+        }
+
+        if (node.name === 'defs') {
+          allDefs.set(node, parentNode);
+          return;
+        }
+
+        if (node.name !== 'linearGradient' && node.name !== 'radialGradient') {
+          return;
+        }
+
+        const stops = node.children.filter((child) => {
+          return child.type === 'element' && child.name === 'stop';
+        });
+
+        const href = node.attributes['xlink:href'] || node.attributes['href'];
+        let effectiveNode =
+          stops.length === 0 && href != null && href.startsWith('#')
+            ? querySelector(root, href)
+            : node;
+
+        if (effectiveNode == null || effectiveNode.type !== 'element') {
+          gradientsToDetach.set(node, parentNode);
+          return;
+        }
+
+        const effectiveStops = effectiveNode.children.filter((child) => {
+          return child.type === 'element' && child.name === 'stop';
+        });
+
+        if (
+          effectiveStops.length !== 1 ||
+          effectiveStops[0].type !== 'element'
+        ) {
+          return;
+        }
+
+        if (parentNode.type === 'element' && parentNode.name === 'defs') {
+          effectedDefs.add(parentNode);
+        }
+
+        gradientsToDetach.set(node, parentNode);
+
+        let color;
+        const style = computeStyle(stylesheet, effectiveStops[0])['stop-color'];
+        if (style != null && style.type === 'static') {
+          color = style.value;
+        }
+
+        const selectorVal = `url(#${node.attributes.id})`;
+
+        const selector = [...colorsProps]
+          .map((attr) => `[${attr}="${selectorVal}"]`)
+          .join(',');
+        const elements = querySelectorAll(root, selector);
+        for (const element of elements) {
+          if (element.type !== 'element') {
+            continue;
+          }
+
+          for (const attr of colorsProps) {
+            if (element.attributes[attr] !== selectorVal) {
+              continue;
+            }
+
+            if (color != null) {
+              element.attributes[attr] = color;
+            } else {
+              delete element.attributes[attr];
+            }
+          }
+        }
+
+        const styledElements = querySelectorAll(
+          root,
+          `[style*=${selectorVal}]`,
+        );
+        for (const element of styledElements) {
+          if (element.type !== 'element') {
+            continue;
+          }
+
+          element.attributes.style = element.attributes.style.replace(
+            selectorVal,
+            color || attrsGroupsDefaults.presentation['stop-color'],
+          );
+        }
+      },
+
+      exit: (node) => {
+        if (node.name === 'svg') {
+          for (const [gradient, parent] of gradientsToDetach.entries()) {
+            if (gradient.attributes['xlink:href'] != null) {
+              xlinkHrefCount--;
+            }
+
+            detachNodeFromParent(gradient, parent);
+          }
+
+          if (xlinkHrefCount === 0) {
+            delete node.attributes['xmlns:xlink'];
+          }
+
+          for (const [defs, parent] of allDefs.entries()) {
+            if (effectedDefs.has(defs) && defs.children.length === 0) {
+              detachNodeFromParent(defs, parent);
+            }
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/convertShapeToPath.js

@@ -0,0 +1,170 @@
+'use strict';
+
+/**
+ * @typedef {import('../lib/types').PathDataItem} PathDataItem
+ */
+
+const { stringifyPathData } = require('../lib/path.js');
+const { detachNodeFromParent } = require('../lib/xast.js');
+
+exports.name = 'convertShapeToPath';
+exports.description = 'converts basic shapes to more compact path form';
+
+const regNumber = /[-+]?(?:\d*\.\d+|\d+\.?)(?:[eE][-+]?\d+)?/g;
+
+/**
+ * Converts basic shape to more compact path.
+ * It also allows further optimizations like
+ * combining paths with similar attributes.
+ *
+ * @see https://www.w3.org/TR/SVG11/shapes.html
+ *
+ * @author Lev Solntsev
+ *
+ * @type {import('./plugins-types').Plugin<'convertShapeToPath'>}
+ */
+exports.fn = (root, params) => {
+  const { convertArcs = false, floatPrecision: precision } = params;
+
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        // convert rect to path
+        if (
+          node.name === 'rect' &&
+          node.attributes.width != null &&
+          node.attributes.height != null &&
+          node.attributes.rx == null &&
+          node.attributes.ry == null
+        ) {
+          const x = Number(node.attributes.x || '0');
+          const y = Number(node.attributes.y || '0');
+          const width = Number(node.attributes.width);
+          const height = Number(node.attributes.height);
+          // Values like '100%' compute to NaN, thus running after
+          // cleanupNumericValues when 'px' units has already been removed.
+          // TODO: Calculate sizes from % and non-px units if possible.
+          if (Number.isNaN(x - y + width - height)) return;
+          /**
+           * @type {PathDataItem[]}
+           */
+          const pathData = [
+            { command: 'M', args: [x, y] },
+            { command: 'H', args: [x + width] },
+            { command: 'V', args: [y + height] },
+            { command: 'H', args: [x] },
+            { command: 'z', args: [] },
+          ];
+          node.name = 'path';
+          node.attributes.d = stringifyPathData({ pathData, precision });
+          delete node.attributes.x;
+          delete node.attributes.y;
+          delete node.attributes.width;
+          delete node.attributes.height;
+        }
+
+        // convert line to path
+        if (node.name === 'line') {
+          const x1 = Number(node.attributes.x1 || '0');
+          const y1 = Number(node.attributes.y1 || '0');
+          const x2 = Number(node.attributes.x2 || '0');
+          const y2 = Number(node.attributes.y2 || '0');
+          if (Number.isNaN(x1 - y1 + x2 - y2)) return;
+          /**
+           * @type {PathDataItem[]}
+           */
+          const pathData = [
+            { command: 'M', args: [x1, y1] },
+            { command: 'L', args: [x2, y2] },
+          ];
+          node.name = 'path';
+          node.attributes.d = stringifyPathData({ pathData, precision });
+          delete node.attributes.x1;
+          delete node.attributes.y1;
+          delete node.attributes.x2;
+          delete node.attributes.y2;
+        }
+
+        // convert polyline and polygon to path
+        if (
+          (node.name === 'polyline' || node.name === 'polygon') &&
+          node.attributes.points != null
+        ) {
+          const coords = (node.attributes.points.match(regNumber) || []).map(
+            Number,
+          );
+          if (coords.length < 4) {
+            detachNodeFromParent(node, parentNode);
+            return;
+          }
+          /**
+           * @type {PathDataItem[]}
+           */
+          const pathData = [];
+          for (let i = 0; i < coords.length; i += 2) {
+            pathData.push({
+              command: i === 0 ? 'M' : 'L',
+              args: coords.slice(i, i + 2),
+            });
+          }
+          if (node.name === 'polygon') {
+            pathData.push({ command: 'z', args: [] });
+          }
+          node.name = 'path';
+          node.attributes.d = stringifyPathData({ pathData, precision });
+          delete node.attributes.points;
+        }
+
+        //  optionally convert circle
+        if (node.name === 'circle' && convertArcs) {
+          const cx = Number(node.attributes.cx || '0');
+          const cy = Number(node.attributes.cy || '0');
+          const r = Number(node.attributes.r || '0');
+          if (Number.isNaN(cx - cy + r)) {
+            return;
+          }
+          /**
+           * @type {PathDataItem[]}
+           */
+          const pathData = [
+            { command: 'M', args: [cx, cy - r] },
+            { command: 'A', args: [r, r, 0, 1, 0, cx, cy + r] },
+            { command: 'A', args: [r, r, 0, 1, 0, cx, cy - r] },
+            { command: 'z', args: [] },
+          ];
+          node.name = 'path';
+          node.attributes.d = stringifyPathData({ pathData, precision });
+          delete node.attributes.cx;
+          delete node.attributes.cy;
+          delete node.attributes.r;
+        }
+
+        // optionally convert ellipse
+        if (node.name === 'ellipse' && convertArcs) {
+          const ecx = Number(node.attributes.cx || '0');
+          const ecy = Number(node.attributes.cy || '0');
+          const rx = Number(node.attributes.rx || '0');
+          const ry = Number(node.attributes.ry || '0');
+          if (Number.isNaN(ecx - ecy + rx - ry)) {
+            return;
+          }
+          /**
+           * @type {PathDataItem[]}
+           */
+          const pathData = [
+            { command: 'M', args: [ecx, ecy - ry] },
+            { command: 'A', args: [rx, ry, 0, 1, 0, ecx, ecy + ry] },
+            { command: 'A', args: [rx, ry, 0, 1, 0, ecx, ecy - ry] },
+            { command: 'z', args: [] },
+          ];
+          node.name = 'path';
+          node.attributes.d = stringifyPathData({ pathData, precision });
+          delete node.attributes.cx;
+          delete node.attributes.cy;
+          delete node.attributes.rx;
+          delete node.attributes.ry;
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/convertStyleToAttrs.js

@@ -0,0 +1,136 @@
+'use strict';
+
+const { attrsGroups } = require('./_collections');
+
+exports.name = 'convertStyleToAttrs';
+exports.description = 'converts style to attributes';
+
+/**
+ * @type {(...args: string[]) => string}
+ */
+const g = (...args) => {
+  return '(?:' + args.join('|') + ')';
+};
+
+const stylingProps = attrsGroups.presentation;
+const rEscape = '\\\\(?:[0-9a-f]{1,6}\\s?|\\r\\n|.)'; // Like \" or \2051. Code points consume one space.
+const rAttr = '\\s*(' + g('[^:;\\\\]', rEscape) + '*?)\\s*'; // attribute name like ‘fill’
+const rSingleQuotes = "'(?:[^'\\n\\r\\\\]|" + rEscape + ")*?(?:'|$)"; // string in single quotes: 'smth'
+const rQuotes = '"(?:[^"\\n\\r\\\\]|' + rEscape + ')*?(?:"|$)'; // string in double quotes: "smth"
+const rQuotedString = new RegExp('^' + g(rSingleQuotes, rQuotes) + '$');
+// Parentheses, E.g.: url(data:image/png;base64,iVBO...).
+// ':' and ';' inside of it should be treated as is. (Just like in strings.)
+const rParenthesis =
+  '\\(' + g('[^\'"()\\\\]+', rEscape, rSingleQuotes, rQuotes) + '*?' + '\\)';
+// The value. It can have strings and parentheses (see above). Fallbacks to anything in case of unexpected input.
+const rValue =
+  '\\s*(' +
+  g(
+    '[^!\'"();\\\\]+?',
+    rEscape,
+    rSingleQuotes,
+    rQuotes,
+    rParenthesis,
+    '[^;]*?',
+  ) +
+  '*?' +
+  ')';
+// End of declaration. Spaces outside of capturing groups help to do natural trimming.
+const rDeclEnd = '\\s*(?:;\\s*|$)';
+// Important rule
+const rImportant = '(\\s*!important(?![-(\\w]))?';
+// Final RegExp to parse CSS declarations.
+const regDeclarationBlock = new RegExp(
+  rAttr + ':' + rValue + rImportant + rDeclEnd,
+  'ig',
+);
+// Comments expression. Honors escape sequences and strings.
+const regStripComments = new RegExp(
+  g(rEscape, rSingleQuotes, rQuotes, '/\\*[^]*?\\*/'),
+  'ig',
+);
+
+/**
+ * Convert style in attributes. Cleanups comments and illegal declarations (without colon) as a side effect.
+ *
+ * @example
+ * <g style="fill:#000; color: #fff;">
+ *             ⬇
+ * <g fill="#000" color="#fff">
+ *
+ * @example
+ * <g style="fill:#000; color: #fff; -webkit-blah: blah">
+ *             ⬇
+ * <g fill="#000" color="#fff" style="-webkit-blah: blah">
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'convertStyleToAttrs'>}
+ */
+exports.fn = (_root, params) => {
+  const { keepImportant = false } = params;
+  return {
+    element: {
+      enter: (node) => {
+        if (node.attributes.style != null) {
+          // ['opacity: 1', 'color: #000']
+          let styles = [];
+          /**
+           * @type {Record<string, string>}
+           */
+          const newAttributes = {};
+
+          // Strip CSS comments preserving escape sequences and strings.
+          const styleValue = node.attributes.style.replace(
+            regStripComments,
+            (match) => {
+              return match[0] == '/'
+                ? ''
+                : match[0] == '\\' && /[-g-z]/i.test(match[1])
+                  ? match[1]
+                  : match;
+            },
+          );
+
+          regDeclarationBlock.lastIndex = 0;
+          for (var rule; (rule = regDeclarationBlock.exec(styleValue)); ) {
+            if (!keepImportant || !rule[3]) {
+              styles.push([rule[1], rule[2]]);
+            }
+          }
+
+          if (styles.length) {
+            styles = styles.filter(function (style) {
+              if (style[0]) {
+                var prop = style[0].toLowerCase(),
+                  val = style[1];
+
+                if (rQuotedString.test(val)) {
+                  val = val.slice(1, -1);
+                }
+
+                if (stylingProps.has(prop)) {
+                  newAttributes[prop] = val;
+
+                  return false;
+                }
+              }
+
+              return true;
+            });
+
+            Object.assign(node.attributes, newAttributes);
+
+            if (styles.length) {
+              node.attributes.style = styles
+                .map((declaration) => declaration.join(':'))
+                .join(';');
+            } else {
+              delete node.attributes.style;
+            }
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/convertTransform.js

@@ -0,0 +1,418 @@
+'use strict';
+
+/**
+ * @typedef {import('../lib/types').XastChild} XastChild
+ * @typedef {import('../lib/types').XastElement} XastElement
+ * @typedef {import('../lib/types').XastParent} XastParent
+ */
+
+const { cleanupOutData, toFixed } = require('../lib/svgo/tools.js');
+const {
+  transform2js,
+  transformsMultiply,
+  matrixToTransform,
+} = require('./_transforms.js');
+
+exports.name = 'convertTransform';
+exports.description = 'collapses multiple transformations and optimizes it';
+
+/**
+ * Convert matrices to the short aliases,
+ * convert long translate, scale or rotate transform notations to the shorts ones,
+ * convert transforms to the matrices and multiply them all into one,
+ * remove useless transforms.
+ *
+ * @see https://www.w3.org/TR/SVG11/coords.html#TransformMatrixDefined
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'convertTransform'>}
+ */
+exports.fn = (_root, params) => {
+  const {
+    convertToShorts = true,
+    // degPrecision = 3, // transformPrecision (or matrix precision) - 2 by default
+    degPrecision,
+    floatPrecision = 3,
+    transformPrecision = 5,
+    matrixToTransform = true,
+    shortTranslate = true,
+    shortScale = true,
+    shortRotate = true,
+    removeUseless = true,
+    collapseIntoOne = true,
+    leadingZero = true,
+    negativeExtraSpace = false,
+  } = params;
+  const newParams = {
+    convertToShorts,
+    degPrecision,
+    floatPrecision,
+    transformPrecision,
+    matrixToTransform,
+    shortTranslate,
+    shortScale,
+    shortRotate,
+    removeUseless,
+    collapseIntoOne,
+    leadingZero,
+    negativeExtraSpace,
+  };
+  return {
+    element: {
+      enter: (node) => {
+        if (node.attributes.transform != null) {
+          convertTransform(node, 'transform', newParams);
+        }
+
+        if (node.attributes.gradientTransform != null) {
+          convertTransform(node, 'gradientTransform', newParams);
+        }
+
+        if (node.attributes.patternTransform != null) {
+          convertTransform(node, 'patternTransform', newParams);
+        }
+      },
+    },
+  };
+};
+
+/**
+ * @typedef {{
+ *   convertToShorts: boolean,
+ *   degPrecision?: number,
+ *   floatPrecision: number,
+ *   transformPrecision: number,
+ *   matrixToTransform: boolean,
+ *   shortTranslate: boolean,
+ *   shortScale: boolean,
+ *   shortRotate: boolean,
+ *   removeUseless: boolean,
+ *   collapseIntoOne: boolean,
+ *   leadingZero: boolean,
+ *   negativeExtraSpace: boolean,
+ * }} TransformParams
+ */
+
+/**
+ * @typedef {{ name: string, data: number[] }} TransformItem
+ */
+
+/**
+ * @param {XastElement} item
+ * @param {string} attrName
+ * @param {TransformParams} params
+ */
+const convertTransform = (item, attrName, params) => {
+  let data = transform2js(item.attributes[attrName]);
+  params = definePrecision(data, params);
+
+  if (params.collapseIntoOne && data.length > 1) {
+    data = [transformsMultiply(data)];
+  }
+
+  if (params.convertToShorts) {
+    data = convertToShorts(data, params);
+  } else {
+    data.forEach((item) => roundTransform(item, params));
+  }
+
+  if (params.removeUseless) {
+    data = removeUseless(data);
+  }
+
+  if (data.length) {
+    item.attributes[attrName] = js2transform(data, params);
+  } else {
+    delete item.attributes[attrName];
+  }
+};
+
+/**
+ * Defines precision to work with certain parts.
+ * transformPrecision - for scale and four first matrix parameters (needs a better precision due to multiplying),
+ * floatPrecision - for translate including two last matrix and rotate parameters,
+ * degPrecision - for rotate and skew. By default it's equal to (roughly)
+ * transformPrecision - 2 or floatPrecision whichever is lower. Can be set in params.
+ *
+ * @type {(data: TransformItem[], params: TransformParams) => TransformParams}
+ *
+ * clone params so it don't affect other elements transformations.
+ */
+const definePrecision = (data, { ...newParams }) => {
+  const matrixData = [];
+  for (const item of data) {
+    if (item.name == 'matrix') {
+      matrixData.push(...item.data.slice(0, 4));
+    }
+  }
+  let numberOfDigits = newParams.transformPrecision;
+  // Limit transform precision with matrix one. Calculating with larger precision doesn't add any value.
+  if (matrixData.length) {
+    newParams.transformPrecision = Math.min(
+      newParams.transformPrecision,
+      Math.max.apply(Math, matrixData.map(floatDigits)) ||
+        newParams.transformPrecision,
+    );
+    numberOfDigits = Math.max.apply(
+      Math,
+      matrixData.map(
+        (n) => n.toString().replace(/\D+/g, '').length, // Number of digits in a number. 123.45 → 5
+      ),
+    );
+  }
+  // No sense in angle precision more then number of significant digits in matrix.
+  if (newParams.degPrecision == null) {
+    newParams.degPrecision = Math.max(
+      0,
+      Math.min(newParams.floatPrecision, numberOfDigits - 2),
+    );
+  }
+  return newParams;
+};
+
+/**
+ * @type {(data: number[], params: TransformParams) => number[]}
+ */
+const degRound = (data, params) => {
+  if (
+    params.degPrecision != null &&
+    params.degPrecision >= 1 &&
+    params.floatPrecision < 20
+  ) {
+    return smartRound(params.degPrecision, data);
+  } else {
+    return round(data);
+  }
+};
+/**
+ * @type {(data: number[], params: TransformParams) => number[]}
+ */
+const floatRound = (data, params) => {
+  if (params.floatPrecision >= 1 && params.floatPrecision < 20) {
+    return smartRound(params.floatPrecision, data);
+  } else {
+    return round(data);
+  }
+};
+
+/**
+ * @type {(data: number[], params: TransformParams) => number[]}
+ */
+const transformRound = (data, params) => {
+  if (params.transformPrecision >= 1 && params.floatPrecision < 20) {
+    return smartRound(params.transformPrecision, data);
+  } else {
+    return round(data);
+  }
+};
+
+/**
+ * Returns number of digits after the point. 0.125 → 3
+ *
+ * @type {(n: number) => number}
+ */
+const floatDigits = (n) => {
+  const str = n.toString();
+  return str.slice(str.indexOf('.')).length - 1;
+};
+
+/**
+ * Convert transforms to the shorthand alternatives.
+ *
+ * @param {TransformItem[]} transforms
+ * @param {TransformParams} params
+ * @returns {TransformItem[]}
+ */
+const convertToShorts = (transforms, params) => {
+  for (var i = 0; i < transforms.length; i++) {
+    let transform = transforms[i];
+
+    // convert matrix to the short aliases
+    if (params.matrixToTransform && transform.name === 'matrix') {
+      var decomposed = matrixToTransform(transform, params);
+      if (
+        js2transform(decomposed, params).length <=
+        js2transform([transform], params).length
+      ) {
+        transforms.splice(i, 1, ...decomposed);
+      }
+      transform = transforms[i];
+    }
+
+    // fixed-point numbers
+    // 12.754997 → 12.755
+    roundTransform(transform, params);
+
+    // convert long translate transform notation to the shorts one
+    // translate(10 0) → translate(10)
+    if (
+      params.shortTranslate &&
+      transform.name === 'translate' &&
+      transform.data.length === 2 &&
+      !transform.data[1]
+    ) {
+      transform.data.pop();
+    }
+
+    // convert long scale transform notation to the shorts one
+    // scale(2 2) → scale(2)
+    if (
+      params.shortScale &&
+      transform.name === 'scale' &&
+      transform.data.length === 2 &&
+      transform.data[0] === transform.data[1]
+    ) {
+      transform.data.pop();
+    }
+
+    // convert long rotate transform notation to the short one
+    // translate(cx cy) rotate(a) translate(-cx -cy) → rotate(a cx cy)
+    if (
+      params.shortRotate &&
+      transforms[i - 2]?.name === 'translate' &&
+      transforms[i - 1].name === 'rotate' &&
+      transforms[i].name === 'translate' &&
+      transforms[i - 2].data[0] === -transforms[i].data[0] &&
+      transforms[i - 2].data[1] === -transforms[i].data[1]
+    ) {
+      transforms.splice(i - 2, 3, {
+        name: 'rotate',
+        data: [
+          transforms[i - 1].data[0],
+          transforms[i - 2].data[0],
+          transforms[i - 2].data[1],
+        ],
+      });
+
+      // splice compensation
+      i -= 2;
+    }
+  }
+
+  return transforms;
+};
+
+/**
+ * Remove useless transforms.
+ *
+ * @type {(transforms: TransformItem[]) => TransformItem[]}
+ */
+const removeUseless = (transforms) => {
+  return transforms.filter((transform) => {
+    // translate(0), rotate(0[, cx, cy]), skewX(0), skewY(0)
+    if (
+      (['translate', 'rotate', 'skewX', 'skewY'].indexOf(transform.name) > -1 &&
+        (transform.data.length == 1 || transform.name == 'rotate') &&
+        !transform.data[0]) ||
+      // translate(0, 0)
+      (transform.name == 'translate' &&
+        !transform.data[0] &&
+        !transform.data[1]) ||
+      // scale(1)
+      (transform.name == 'scale' &&
+        transform.data[0] == 1 &&
+        (transform.data.length < 2 || transform.data[1] == 1)) ||
+      // matrix(1 0 0 1 0 0)
+      (transform.name == 'matrix' &&
+        transform.data[0] == 1 &&
+        transform.data[3] == 1 &&
+        !(
+          transform.data[1] ||
+          transform.data[2] ||
+          transform.data[4] ||
+          transform.data[5]
+        ))
+    ) {
+      return false;
+    }
+
+    return true;
+  });
+};
+
+/**
+ * Convert transforms JS representation to string.
+ *
+ * @param {TransformItem[]} transformJS
+ * @param {TransformParams} params
+ * @returns {string}
+ */
+const js2transform = (transformJS, params) => {
+  const transformString = transformJS
+    .map((transform) => {
+      roundTransform(transform, params);
+      return `${transform.name}(${cleanupOutData(transform.data, params)})`;
+    })
+    .join('');
+
+  return transformString;
+};
+
+/**
+ * @type {(transform: TransformItem, params: TransformParams) => TransformItem}
+ */
+const roundTransform = (transform, params) => {
+  switch (transform.name) {
+    case 'translate':
+      transform.data = floatRound(transform.data, params);
+      break;
+    case 'rotate':
+      transform.data = [
+        ...degRound(transform.data.slice(0, 1), params),
+        ...floatRound(transform.data.slice(1), params),
+      ];
+      break;
+    case 'skewX':
+    case 'skewY':
+      transform.data = degRound(transform.data, params);
+      break;
+    case 'scale':
+      transform.data = transformRound(transform.data, params);
+      break;
+    case 'matrix':
+      transform.data = [
+        ...transformRound(transform.data.slice(0, 4), params),
+        ...floatRound(transform.data.slice(4), params),
+      ];
+      break;
+  }
+  return transform;
+};
+
+/**
+ * Rounds numbers in array.
+ *
+ * @type {(data: number[]) => number[]}
+ */
+const round = (data) => {
+  return data.map(Math.round);
+};
+
+/**
+ * Decrease accuracy of floating-point numbers
+ * in transforms keeping a specified number of decimals.
+ * Smart rounds values like 2.349 to 2.35.
+ *
+ * @param {number} precision
+ * @param {number[]} data
+ * @returns {number[]}
+ */
+const smartRound = (precision, data) => {
+  for (
+    var i = data.length,
+      tolerance = +Math.pow(0.1, precision).toFixed(precision);
+    i--;
+
+  ) {
+    if (toFixed(data[i], precision) !== data[i]) {
+      var rounded = +data[i].toFixed(precision - 1);
+      data[i] =
+        +Math.abs(rounded - data[i]).toFixed(precision + 1) >= tolerance
+          ? +data[i].toFixed(precision)
+          : rounded;
+    }
+  }
+
+  return data;
+};

backend/node_modules/svgo/plugins/inlineStyles.js

@@ -0,0 +1,390 @@
+'use strict';
+
+/**
+ * @typedef {import('../lib/types').XastElement} XastElement
+ * @typedef {import('../lib/types').XastParent} XastParent
+ */
+
+const csstree = require('css-tree');
+const {
+  syntax: { specificity },
+} = require('csso');
+const {
+  visitSkip,
+  querySelectorAll,
+  detachNodeFromParent,
+} = require('../lib/xast.js');
+const { compareSpecificity, includesAttrSelector } = require('../lib/style');
+const { attrsGroups, pseudoClasses } = require('./_collections');
+
+exports.name = 'inlineStyles';
+exports.description = 'inline styles (additional options)';
+
+/**
+ * Some pseudo-classes can only be calculated by clients, like :visited,
+ * :future, or :hover, but there are other pseudo-classes that we can evaluate
+ * during optimization.
+ *
+ * The list of pseudo-classes that we can evaluate during optimization, and so
+ * shouldn't be toggled conditionally through the `usePseudos` parameter.
+ *
+ * @see https://developer.mozilla.org/docs/Web/CSS/Pseudo-classes
+ */
+const preservedPseudos = [
+  ...pseudoClasses.functional,
+  ...pseudoClasses.treeStructural,
+];
+
+/**
+ * Merges styles from style nodes into inline styles.
+ *
+ * @type {import('./plugins-types').Plugin<'inlineStyles'>}
+ * @author strarsis <strarsis@gmail.com>
+ */
+exports.fn = (root, params) => {
+  const {
+    onlyMatchedOnce = true,
+    removeMatchedSelectors = true,
+    useMqs = ['', 'screen'],
+    usePseudos = [''],
+  } = params;
+
+  /**
+   * @type {{ node: XastElement, parentNode: XastParent, cssAst: csstree.StyleSheet }[]}
+   */
+  const styles = [];
+  /**
+   * @type {{
+   *   node: csstree.Selector,
+   *   item: csstree.ListItem<csstree.CssNode>,
+   *   rule: csstree.Rule,
+   *   matchedElements?: XastElement[]
+   * }[]}
+   */
+  let selectors = [];
+
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        if (node.name === 'foreignObject') {
+          return visitSkip;
+        }
+        if (node.name !== 'style' || node.children.length === 0) {
+          return;
+        }
+        if (
+          node.attributes.type != null &&
+          node.attributes.type !== '' &&
+          node.attributes.type !== 'text/css'
+        ) {
+          return;
+        }
+
+        const cssText = node.children
+          .filter((child) => child.type === 'text' || child.type === 'cdata')
+          // @ts-ignore
+          .map((child) => child.value)
+          .join('');
+
+        /** @type {?csstree.CssNode} */
+        let cssAst = null;
+        try {
+          cssAst = csstree.parse(cssText, {
+            parseValue: false,
+            parseCustomProperty: false,
+          });
+        } catch {
+          return;
+        }
+        if (cssAst.type === 'StyleSheet') {
+          styles.push({ node, parentNode, cssAst });
+        }
+
+        // collect selectors
+        csstree.walk(cssAst, {
+          visit: 'Rule',
+          enter(node) {
+            const atrule = this.atrule;
+
+            // skip media queries not included into useMqs param
+            let mediaQuery = '';
+            if (atrule != null) {
+              mediaQuery = atrule.name;
+              if (atrule.prelude != null) {
+                mediaQuery += ` ${csstree.generate(atrule.prelude)}`;
+              }
+            }
+            if (!useMqs.includes(mediaQuery)) {
+              return;
+            }
+
+            if (node.prelude.type === 'SelectorList') {
+              node.prelude.children.forEach((childNode, item) => {
+                if (childNode.type === 'Selector') {
+                  /**
+                   * @type {{
+                   *   item: csstree.ListItem<csstree.CssNode>,
+                   *   list: csstree.List<csstree.CssNode>
+                   * }[]}
+                   */
+                  const pseudos = [];
+
+                  childNode.children.forEach(
+                    (grandchildNode, grandchildItem, grandchildList) => {
+                      const isPseudo =
+                        grandchildNode.type === 'PseudoClassSelector' ||
+                        grandchildNode.type === 'PseudoElementSelector';
+
+                      if (
+                        isPseudo &&
+                        !preservedPseudos.includes(grandchildNode.name)
+                      ) {
+                        pseudos.push({
+                          item: grandchildItem,
+                          list: grandchildList,
+                        });
+                      }
+                    },
+                  );
+
+                  const pseudoSelectors = csstree.generate({
+                    type: 'Selector',
+                    children: new csstree.List().fromArray(
+                      pseudos.map((pseudo) => pseudo.item.data),
+                    ),
+                  });
+
+                  if (usePseudos.includes(pseudoSelectors)) {
+                    for (const pseudo of pseudos) {
+                      pseudo.list.remove(pseudo.item);
+                    }
+                  }
+
+                  selectors.push({ node: childNode, rule: node, item: item });
+                }
+              });
+            }
+          },
+        });
+      },
+    },
+
+    root: {
+      exit: () => {
+        if (styles.length === 0) {
+          return;
+        }
+        const sortedSelectors = selectors
+          .slice()
+          .sort((a, b) => {
+            const aSpecificity = specificity(a.item.data);
+            const bSpecificity = specificity(b.item.data);
+            return compareSpecificity(aSpecificity, bSpecificity);
+          })
+          .reverse();
+
+        for (const selector of sortedSelectors) {
+          // match selectors
+          const selectorText = csstree.generate(selector.item.data);
+          /** @type {XastElement[]} */
+          const matchedElements = [];
+          try {
+            for (const node of querySelectorAll(root, selectorText)) {
+              if (node.type === 'element') {
+                matchedElements.push(node);
+              }
+            }
+          } catch (selectError) {
+            continue;
+          }
+          // nothing selected
+          if (matchedElements.length === 0) {
+            continue;
+          }
+
+          // apply styles to matched elements
+          // skip selectors that match more than once if option onlyMatchedOnce is enabled
+          if (onlyMatchedOnce && matchedElements.length > 1) {
+            continue;
+          }
+
+          // apply <style/> to matched elements
+          for (const selectedEl of matchedElements) {
+            const styleDeclarationList = csstree.parse(
+              selectedEl.attributes.style ?? '',
+              {
+                context: 'declarationList',
+                parseValue: false,
+              },
+            );
+            if (styleDeclarationList.type !== 'DeclarationList') {
+              continue;
+            }
+            const styleDeclarationItems = new Map();
+
+            /** @type {csstree.ListItem<csstree.CssNode>} */
+            let firstListItem;
+
+            csstree.walk(styleDeclarationList, {
+              visit: 'Declaration',
+              enter(node, item) {
+                if (firstListItem == null) {
+                  firstListItem = item;
+                }
+
+                styleDeclarationItems.set(node.property.toLowerCase(), item);
+              },
+            });
+            // merge declarations
+            csstree.walk(selector.rule, {
+              visit: 'Declaration',
+              enter(ruleDeclaration) {
+                // existing inline styles have higher priority
+                // no inline styles, external styles,                                    external styles used
+                // inline styles,    external styles same   priority as inline styles,   inline   styles used
+                // inline styles,    external styles higher priority than inline styles, external styles used
+                const property = ruleDeclaration.property;
+
+                if (
+                  attrsGroups.presentation.has(property) &&
+                  !selectors.some((selector) =>
+                    includesAttrSelector(selector.item, property),
+                  )
+                ) {
+                  delete selectedEl.attributes[property];
+                }
+
+                const matchedItem = styleDeclarationItems.get(property);
+                const ruleDeclarationItem =
+                  styleDeclarationList.children.createItem(ruleDeclaration);
+                if (matchedItem == null) {
+                  styleDeclarationList.children.insert(
+                    ruleDeclarationItem,
+                    firstListItem,
+                  );
+                } else if (
+                  matchedItem.data.important !== true &&
+                  ruleDeclaration.important === true
+                ) {
+                  styleDeclarationList.children.replace(
+                    matchedItem,
+                    ruleDeclarationItem,
+                  );
+                  styleDeclarationItems.set(property, ruleDeclarationItem);
+                }
+              },
+            });
+
+            const newStyles = csstree.generate(styleDeclarationList);
+            if (newStyles.length !== 0) {
+              selectedEl.attributes.style = newStyles;
+            }
+          }
+
+          if (
+            removeMatchedSelectors &&
+            matchedElements.length !== 0 &&
+            selector.rule.prelude.type === 'SelectorList'
+          ) {
+            // clean up matching simple selectors if option removeMatchedSelectors is enabled
+            selector.rule.prelude.children.remove(selector.item);
+          }
+          selector.matchedElements = matchedElements;
+        }
+
+        // no further processing required
+        if (!removeMatchedSelectors) {
+          return;
+        }
+
+        // clean up matched class + ID attribute values
+        for (const selector of sortedSelectors) {
+          if (selector.matchedElements == null) {
+            continue;
+          }
+
+          if (onlyMatchedOnce && selector.matchedElements.length > 1) {
+            // skip selectors that match more than once if option onlyMatchedOnce is enabled
+            continue;
+          }
+
+          for (const selectedEl of selector.matchedElements) {
+            // class
+            const classList = new Set(
+              selectedEl.attributes.class == null
+                ? null
+                : selectedEl.attributes.class.split(' '),
+            );
+
+            for (const child of selector.node.children) {
+              if (
+                child.type === 'ClassSelector' &&
+                !selectors.some((selector) =>
+                  includesAttrSelector(
+                    selector.item,
+                    'class',
+                    child.name,
+                    true,
+                  ),
+                )
+              ) {
+                classList.delete(child.name);
+              }
+            }
+
+            if (classList.size === 0) {
+              delete selectedEl.attributes.class;
+            } else {
+              selectedEl.attributes.class = Array.from(classList).join(' ');
+            }
+
+            // ID
+            const firstSubSelector = selector.node.children.first;
+            if (
+              firstSubSelector?.type === 'IdSelector' &&
+              selectedEl.attributes.id === firstSubSelector.name &&
+              !selectors.some((selector) =>
+                includesAttrSelector(
+                  selector.item,
+                  'id',
+                  firstSubSelector.name,
+                  true,
+                ),
+              )
+            ) {
+              delete selectedEl.attributes.id;
+            }
+          }
+        }
+
+        for (const style of styles) {
+          csstree.walk(style.cssAst, {
+            visit: 'Rule',
+            enter: function (node, item, list) {
+              // clean up <style/> rulesets without any css selectors left
+              if (
+                node.type === 'Rule' &&
+                node.prelude.type === 'SelectorList' &&
+                node.prelude.children.isEmpty
+              ) {
+                list.remove(item);
+              }
+            },
+          });
+
+          // csstree v2 changed this type
+          if (style.cssAst.children.isEmpty) {
+            // remove empty style element
+            detachNodeFromParent(style.node, style.parentNode);
+          } else {
+            // update style element if any styles left
+            const firstChild = style.node.children[0];
+            if (firstChild.type === 'text' || firstChild.type === 'cdata') {
+              firstChild.value = csstree.generate(style.cssAst);
+            }
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/mergePaths.js

@@ -0,0 +1,148 @@
+'use strict';
+
+/**
+ * @typedef {import("../lib/types").PathDataItem} PathDataItem
+ * @typedef {import('../lib/types').XastChild} XastChild
+ * @typedef {import('../lib/types').XastElement} XastElement
+ */
+
+const { collectStylesheet, computeStyle } = require('../lib/style.js');
+const { path2js, js2path, intersects } = require('./_path.js');
+
+exports.name = 'mergePaths';
+exports.description = 'merges multiple paths in one if possible';
+
+/**
+ * Merge multiple Paths into one.
+ *
+ * @author Kir Belevich, Lev Solntsev
+ *
+ * @type {import('./plugins-types').Plugin<'mergePaths'>}
+ */
+exports.fn = (root, params) => {
+  const {
+    force = false,
+    floatPrecision,
+    noSpaceAfterFlags = false, // a20 60 45 0 1 30 20 → a20 60 45 0130 20
+  } = params;
+  const stylesheet = collectStylesheet(root);
+
+  return {
+    element: {
+      enter: (node) => {
+        if (node.children.length <= 1) {
+          return;
+        }
+
+        /** @type {XastChild[]} */
+        const elementsToRemove = [];
+        let prevChild = node.children[0];
+        let prevPathData = null;
+
+        /**
+         * @param {XastElement} child
+         * @param {PathDataItem[]} pathData
+         */
+        const updatePreviousPath = (child, pathData) => {
+          js2path(child, pathData, {
+            floatPrecision,
+            noSpaceAfterFlags,
+          });
+          prevPathData = null;
+        };
+
+        for (let i = 1; i < node.children.length; i++) {
+          const child = node.children[i];
+
+          if (
+            prevChild.type !== 'element' ||
+            prevChild.name !== 'path' ||
+            prevChild.children.length !== 0 ||
+            prevChild.attributes.d == null
+          ) {
+            if (prevPathData && prevChild.type === 'element') {
+              updatePreviousPath(prevChild, prevPathData);
+            }
+            prevChild = child;
+            continue;
+          }
+
+          if (
+            child.type !== 'element' ||
+            child.name !== 'path' ||
+            child.children.length !== 0 ||
+            child.attributes.d == null
+          ) {
+            if (prevPathData) {
+              updatePreviousPath(prevChild, prevPathData);
+            }
+            prevChild = child;
+            continue;
+          }
+
+          const computedStyle = computeStyle(stylesheet, child);
+          if (
+            computedStyle['marker-start'] ||
+            computedStyle['marker-mid'] ||
+            computedStyle['marker-end']
+          ) {
+            if (prevPathData) {
+              updatePreviousPath(prevChild, prevPathData);
+            }
+            prevChild = child;
+            continue;
+          }
+          const childAttrs = Object.keys(child.attributes);
+          if (childAttrs.length !== Object.keys(prevChild.attributes).length) {
+            if (prevPathData) {
+              updatePreviousPath(prevChild, prevPathData);
+            }
+            prevChild = child;
+            continue;
+          }
+
+          const areAttrsEqual = childAttrs.some((attr) => {
+            return (
+              attr !== 'd' &&
+              prevChild.type === 'element' &&
+              prevChild.attributes[attr] !== child.attributes[attr]
+            );
+          });
+
+          if (areAttrsEqual) {
+            if (prevPathData) {
+              updatePreviousPath(prevChild, prevPathData);
+            }
+            prevChild = child;
+            continue;
+          }
+
+          const hasPrevPath = prevPathData != null;
+          const currentPathData = path2js(child);
+          prevPathData = prevPathData ?? path2js(prevChild);
+
+          if (force || !intersects(prevPathData, currentPathData)) {
+            prevPathData.push(...currentPathData);
+            elementsToRemove.push(child);
+            continue;
+          }
+
+          if (hasPrevPath) {
+            updatePreviousPath(prevChild, prevPathData);
+          }
+
+          prevChild = child;
+          prevPathData = null;
+        }
+
+        if (prevPathData && prevChild.type === 'element') {
+          updatePreviousPath(prevChild, prevPathData);
+        }
+
+        node.children = node.children.filter(
+          (child) => !elementsToRemove.includes(child),
+        );
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/mergeStyles.js

@@ -0,0 +1,98 @@
+'use strict';
+
+/**
+ * @typedef {import('../lib/types').XastElement} XastElement
+ * @typedef {import('../lib/types').XastChild} XastChild
+ */
+
+const { visitSkip, detachNodeFromParent } = require('../lib/xast.js');
+
+exports.name = 'mergeStyles';
+exports.description = 'merge multiple style elements into one';
+
+/**
+ * Merge multiple style elements into one.
+ *
+ * @author strarsis <strarsis@gmail.com>
+ *
+ * @type {import('./plugins-types').Plugin<'mergeStyles'>}
+ */
+exports.fn = () => {
+  /**
+   * @type {?XastElement}
+   */
+  let firstStyleElement = null;
+  let collectedStyles = '';
+  /**
+   * @type {'text' | 'cdata'}
+   */
+  let styleContentType = 'text';
+
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        // skip <foreignObject> content
+        if (node.name === 'foreignObject') {
+          return visitSkip;
+        }
+
+        // collect style elements
+        if (node.name !== 'style') {
+          return;
+        }
+
+        // skip <style> with invalid type attribute
+        if (
+          node.attributes.type != null &&
+          node.attributes.type !== '' &&
+          node.attributes.type !== 'text/css'
+        ) {
+          return;
+        }
+
+        // extract style element content
+        let css = '';
+        for (const child of node.children) {
+          if (child.type === 'text') {
+            css += child.value;
+          }
+          if (child.type === 'cdata') {
+            styleContentType = 'cdata';
+            css += child.value;
+          }
+        }
+
+        // remove empty style elements
+        if (css.trim().length === 0) {
+          detachNodeFromParent(node, parentNode);
+          return;
+        }
+
+        // collect css and wrap with media query if present in attribute
+        if (node.attributes.media == null) {
+          collectedStyles += css;
+        } else {
+          collectedStyles += `@media ${node.attributes.media}{${css}}`;
+          delete node.attributes.media;
+        }
+
+        // combine collected styles in the first style element
+        if (firstStyleElement == null) {
+          firstStyleElement = node;
+        } else {
+          detachNodeFromParent(node, parentNode);
+          /**
+           * @type {XastChild}
+           */
+          const child = { type: styleContentType, value: collectedStyles };
+          // TODO remove legacy parentNode in v4
+          Object.defineProperty(child, 'parentNode', {
+            writable: true,
+            value: firstStyleElement,
+          });
+          firstStyleElement.children = [child];
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/minifyStyles.js

@@ -0,0 +1,141 @@
+'use strict';
+
+/**
+ * @typedef {import('../lib/types').XastElement} XastElement
+ * @typedef {import('../lib/types').XastParent} XastParent
+ */
+
+const csso = require('csso');
+const { detachNodeFromParent } = require('../lib/xast');
+const { hasScripts } = require('../lib/svgo/tools');
+
+exports.name = 'minifyStyles';
+exports.description = 'minifies styles and removes unused styles';
+
+/**
+ * Minifies styles (<style> element + style attribute) using CSSO.
+ *
+ * @author strarsis <strarsis@gmail.com>
+ * @type {import('./plugins-types').Plugin<'minifyStyles'>}
+ */
+exports.fn = (_root, { usage, ...params }) => {
+  /** @type {Map<XastElement, XastParent>} */
+  const styleElements = new Map();
+
+  /** @type {XastElement[]} */
+  const elementsWithStyleAttributes = [];
+
+  /** @type {Set<string>} */
+  const tagsUsage = new Set();
+
+  /** @type {Set<string>} */
+  const idsUsage = new Set();
+
+  /** @type {Set<string>} */
+  const classesUsage = new Set();
+
+  let enableTagsUsage = true;
+  let enableIdsUsage = true;
+  let enableClassesUsage = true;
+
+  /**
+   * Force to use usage data even if it unsafe. For example, the document
+   * contains scripts or in attributes..
+   */
+  let forceUsageDeoptimized = false;
+
+  if (typeof usage === 'boolean') {
+    enableTagsUsage = usage;
+    enableIdsUsage = usage;
+    enableClassesUsage = usage;
+  } else if (usage) {
+    enableTagsUsage = usage.tags == null ? true : usage.tags;
+    enableIdsUsage = usage.ids == null ? true : usage.ids;
+    enableClassesUsage = usage.classes == null ? true : usage.classes;
+    forceUsageDeoptimized = usage.force == null ? false : usage.force;
+  }
+
+  let deoptimized = false;
+
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        // detect deoptimisations
+        if (hasScripts(node)) {
+          deoptimized = true;
+        }
+
+        // collect tags, ids and classes usage
+        tagsUsage.add(node.name);
+        if (node.attributes.id != null) {
+          idsUsage.add(node.attributes.id);
+        }
+        if (node.attributes.class != null) {
+          for (const className of node.attributes.class.split(/\s+/)) {
+            classesUsage.add(className);
+          }
+        }
+        // collect style elements or elements with style attribute
+        if (node.name === 'style' && node.children.length !== 0) {
+          styleElements.set(node, parentNode);
+        } else if (node.attributes.style != null) {
+          elementsWithStyleAttributes.push(node);
+        }
+      },
+    },
+
+    root: {
+      exit: () => {
+        /** @type {csso.Usage} */
+        const cssoUsage = {};
+        if (!deoptimized || forceUsageDeoptimized) {
+          if (enableTagsUsage) {
+            cssoUsage.tags = Array.from(tagsUsage);
+          }
+          if (enableIdsUsage) {
+            cssoUsage.ids = Array.from(idsUsage);
+          }
+          if (enableClassesUsage) {
+            cssoUsage.classes = Array.from(classesUsage);
+          }
+        }
+        // minify style elements
+        for (const [styleNode, styleNodeParent] of styleElements.entries()) {
+          if (
+            styleNode.children[0].type === 'text' ||
+            styleNode.children[0].type === 'cdata'
+          ) {
+            const cssText = styleNode.children[0].value;
+            const minified = csso.minify(cssText, {
+              ...params,
+              usage: cssoUsage,
+            }).css;
+
+            if (minified.length === 0) {
+              detachNodeFromParent(styleNode, styleNodeParent);
+              continue;
+            }
+
+            // preserve cdata if necessary
+            // TODO split cdata -> text optimisation into separate plugin
+            if (cssText.indexOf('>') >= 0 || cssText.indexOf('<') >= 0) {
+              styleNode.children[0].type = 'cdata';
+              styleNode.children[0].value = minified;
+            } else {
+              styleNode.children[0].type = 'text';
+              styleNode.children[0].value = minified;
+            }
+          }
+        }
+        // minify style attributes
+        for (const node of elementsWithStyleAttributes) {
+          // style attribute
+          const elemStyle = node.attributes.style;
+          node.attributes.style = csso.minifyBlock(elemStyle, {
+            ...params,
+          }).css;
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/moveElemsAttrsToGroup.js

@@ -0,0 +1,128 @@
+'use strict';
+
+const { visit } = require('../lib/xast.js');
+const { inheritableAttrs, pathElems } = require('./_collections.js');
+
+exports.name = 'moveElemsAttrsToGroup';
+exports.description = 'Move common attributes of group children to the group';
+
+/**
+ * Move common attributes of group children to the group
+ *
+ * @example
+ * <g attr1="val1">
+ *     <g attr2="val2">
+ *         text
+ *     </g>
+ *     <circle attr2="val2" attr3="val3"/>
+ * </g>
+ *              ⬇
+ * <g attr1="val1" attr2="val2">
+ *     <g>
+ *         text
+ *     </g>
+ *    <circle attr3="val3"/>
+ * </g>
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'moveElemsAttrsToGroup'>}
+ */
+exports.fn = (root) => {
+  // find if any style element is present
+  let deoptimizedWithStyles = false;
+  visit(root, {
+    element: {
+      enter: (node) => {
+        if (node.name === 'style') {
+          deoptimizedWithStyles = true;
+        }
+      },
+    },
+  });
+
+  return {
+    element: {
+      exit: (node) => {
+        // process only groups with more than 1 children
+        if (node.name !== 'g' || node.children.length <= 1) {
+          return;
+        }
+
+        // deoptimize the plugin when style elements are present
+        // selectors may rely on id, classes or tag names
+        if (deoptimizedWithStyles) {
+          return;
+        }
+
+        /**
+         * find common attributes in group children
+         * @type {Map<string, string>}
+         */
+        const commonAttributes = new Map();
+        let initial = true;
+        let everyChildIsPath = true;
+        for (const child of node.children) {
+          if (child.type === 'element') {
+            if (!pathElems.has(child.name)) {
+              everyChildIsPath = false;
+            }
+            if (initial) {
+              initial = false;
+              // collect all inheritable attributes from first child element
+              for (const [name, value] of Object.entries(child.attributes)) {
+                // consider only inheritable attributes
+                if (inheritableAttrs.has(name)) {
+                  commonAttributes.set(name, value);
+                }
+              }
+            } else {
+              // exclude uncommon attributes from initial list
+              for (const [name, value] of commonAttributes) {
+                if (child.attributes[name] !== value) {
+                  commonAttributes.delete(name);
+                }
+              }
+            }
+          }
+        }
+
+        // preserve transform on children when group has clip-path or mask
+        if (
+          node.attributes['clip-path'] != null ||
+          node.attributes.mask != null
+        ) {
+          commonAttributes.delete('transform');
+        }
+
+        // preserve transform when all children are paths
+        // so the transform could be applied to path data by other plugins
+        if (everyChildIsPath) {
+          commonAttributes.delete('transform');
+        }
+
+        // add common children attributes to group
+        for (const [name, value] of commonAttributes) {
+          if (name === 'transform') {
+            if (node.attributes.transform != null) {
+              node.attributes.transform = `${node.attributes.transform} ${value}`;
+            } else {
+              node.attributes.transform = value;
+            }
+          } else {
+            node.attributes[name] = value;
+          }
+        }
+
+        // delete common attributes from children
+        for (const child of node.children) {
+          if (child.type === 'element') {
+            for (const [name] of commonAttributes) {
+              delete child.attributes[name];
+            }
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/moveGroupAttrsToElems.js

@@ -0,0 +1,65 @@
+'use strict';
+
+const { pathElems, referencesProps } = require('./_collections.js');
+const { includesUrlReference } = require('../lib/svgo/tools.js');
+
+exports.name = 'moveGroupAttrsToElems';
+exports.description = 'moves some group attributes to the content elements';
+
+const pathElemsWithGroupsAndText = [...pathElems, 'g', 'text'];
+
+/**
+ * Move group attrs to the content elements.
+ *
+ * @example
+ * <g transform="scale(2)">
+ *     <path transform="rotate(45)" d="M0,0 L10,20"/>
+ *     <path transform="translate(10, 20)" d="M0,10 L20,30"/>
+ * </g>
+ *                          ⬇
+ * <g>
+ *     <path transform="scale(2) rotate(45)" d="M0,0 L10,20"/>
+ *     <path transform="scale(2) translate(10, 20)" d="M0,10 L20,30"/>
+ * </g>
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'moveGroupAttrsToElems'>}
+ */
+exports.fn = () => {
+  return {
+    element: {
+      enter: (node) => {
+        // move group transform attr to content's pathElems
+        if (
+          node.name === 'g' &&
+          node.children.length !== 0 &&
+          node.attributes.transform != null &&
+          Object.entries(node.attributes).some(
+            ([name, value]) =>
+              referencesProps.has(name) && includesUrlReference(value),
+          ) === false &&
+          node.children.every(
+            (child) =>
+              child.type === 'element' &&
+              pathElemsWithGroupsAndText.includes(child.name) &&
+              child.attributes.id == null,
+          )
+        ) {
+          for (const child of node.children) {
+            const value = node.attributes.transform;
+            if (child.type === 'element') {
+              if (child.attributes.transform != null) {
+                child.attributes.transform = `${value} ${child.attributes.transform}`;
+              } else {
+                child.attributes.transform = value;
+              }
+            }
+          }
+
+          delete node.attributes.transform;
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/plugins-types.d.ts

@@ -0,0 +1,291 @@
+import type {
+  Plugin as PluginDef,
+  PluginInfo,
+  XastElement,
+} from '../lib/types';
+
+type DefaultPlugins = {
+  cleanupAttrs: {
+    newlines?: boolean;
+    trim?: boolean;
+    spaces?: boolean;
+  };
+  cleanupEnableBackground: void;
+  cleanupIds: {
+    remove?: boolean;
+    minify?: boolean;
+    preserve?: string[];
+    preservePrefixes?: string[];
+    force?: boolean;
+  };
+  cleanupNumericValues: {
+    floatPrecision?: number;
+    leadingZero?: boolean;
+    defaultPx?: boolean;
+    convertToPx?: boolean;
+  };
+  collapseGroups: void;
+  convertColors: {
+    currentColor?: boolean | string | RegExp;
+    names2hex?: boolean;
+    rgb2hex?: boolean;
+    shorthex?: boolean;
+    shortname?: boolean;
+  };
+  convertEllipseToCircle: void;
+  convertPathData: {
+    applyTransforms?: boolean;
+    applyTransformsStroked?: boolean;
+    makeArcs?: {
+      threshold: number;
+      tolerance: number;
+    };
+    straightCurves?: boolean;
+    convertToQ?: boolean;
+    lineShorthands?: boolean;
+    convertToZ?: boolean;
+    curveSmoothShorthands?: boolean;
+    floatPrecision?: number | false;
+    transformPrecision?: number;
+    smartArcRounding?: boolean;
+    removeUseless?: boolean;
+    collapseRepeated?: boolean;
+    utilizeAbsolute?: boolean;
+    leadingZero?: boolean;
+    negativeExtraSpace?: boolean;
+    noSpaceAfterFlags?: boolean;
+    forceAbsolutePath?: boolean;
+  };
+  convertShapeToPath: {
+    convertArcs?: boolean;
+    floatPrecision?: number;
+  };
+  convertTransform: {
+    convertToShorts?: boolean;
+    degPrecision?: number;
+    floatPrecision?: number;
+    transformPrecision?: number;
+    matrixToTransform?: boolean;
+    shortTranslate?: boolean;
+    shortScale?: boolean;
+    shortRotate?: boolean;
+    removeUseless?: boolean;
+    collapseIntoOne?: boolean;
+    leadingZero?: boolean;
+    negativeExtraSpace?: boolean;
+  };
+  mergeStyles: void;
+  inlineStyles: {
+    /**
+     * Inlines selectors that match once only.
+     *
+     * @default true
+     */
+    onlyMatchedOnce?: boolean;
+    /**
+     * Clean up matched selectors. Unused selects are left as-is.
+     *
+     * @default true
+     */
+    removeMatchedSelectors?: boolean;
+    /**
+     * Media queries to use. An empty string indicates all selectors outside of
+     * media queries.
+     */
+    useMqs?: string[];
+    /**
+     * Pseudo-classes and elements to use. An empty string indicates all
+     * all non-pseudo-classes and elements.
+     */
+    usePseudos?: string[];
+  };
+  mergePaths: {
+    force?: boolean;
+    floatPrecision?: number;
+    noSpaceAfterFlags?: boolean;
+  };
+
+  minifyStyles: {
+    /**
+     * Disable or enable a structure optimisations.
+     * @default true
+     */
+    restructure?: boolean;
+    /**
+     * Enables merging of @media rules with the same media query split by other rules.
+     * The optimisation is unsafe in general, but should work fine in most cases. Use it on your own risk.
+     * @default false
+     */
+    forceMediaMerge?: boolean;
+    /**
+     * Specify what comments to leave:
+     * - 'exclamation' or true – leave all exclamation comments
+     * - 'first-exclamation' – remove every comment except first one
+     * - false – remove all comments
+     * @default true
+     */
+    comments?: string | boolean;
+    /**
+     * Advanced optimizations
+     */
+    usage?:
+      | boolean
+      | {
+          force?: boolean;
+          ids?: boolean;
+          classes?: boolean;
+          tags?: boolean;
+        };
+  };
+
+  moveElemsAttrsToGroup: void;
+  moveGroupAttrsToElems: void;
+  removeComments: {
+    preservePatterns: Array<RegExp | string> | false;
+  };
+  removeDesc: {
+    removeAny?: boolean;
+  };
+  removeDoctype: void;
+  removeEditorsNSData: {
+    additionalNamespaces?: string[];
+  };
+  removeEmptyAttrs: void;
+  removeEmptyContainers: void;
+  removeEmptyText: {
+    text?: boolean;
+    tspan?: boolean;
+    tref?: boolean;
+  };
+  removeHiddenElems: {
+    isHidden?: boolean;
+    displayNone?: boolean;
+    opacity0?: boolean;
+    circleR0?: boolean;
+    ellipseRX0?: boolean;
+    ellipseRY0?: boolean;
+    rectWidth0?: boolean;
+    rectHeight0?: boolean;
+    patternWidth0?: boolean;
+    patternHeight0?: boolean;
+    imageWidth0?: boolean;
+    imageHeight0?: boolean;
+    pathEmptyD?: boolean;
+    polylineEmptyPoints?: boolean;
+    polygonEmptyPoints?: boolean;
+  };
+  removeMetadata: void;
+  removeNonInheritableGroupAttrs: void;
+  removeTitle: void;
+  removeUnknownsAndDefaults: {
+    unknownContent?: boolean;
+    unknownAttrs?: boolean;
+    defaultAttrs?: boolean;
+    /**
+     * If to remove XML declarations that are assigned their default value. XML
+     * declarations are the properties in the `<?xml … ?>` block at the top of
+     * the document.
+     */
+    defaultMarkupDeclarations?: boolean;
+    uselessOverrides?: boolean;
+    keepDataAttrs?: boolean;
+    keepAriaAttrs?: boolean;
+    keepRoleAttr?: boolean;
+  };
+  removeUnusedNS: void;
+  removeUselessDefs: void;
+  removeUselessStrokeAndFill: {
+    stroke?: boolean;
+    fill?: boolean;
+    removeNone?: boolean;
+  };
+  removeViewBox: void;
+  removeXMLProcInst: void;
+  sortAttrs: {
+    order?: string[];
+    xmlnsOrder?: 'front' | 'alphabetical';
+  };
+  sortDefsChildren: void;
+};
+
+type PresetDefaultOverrides = {
+  [Name in keyof DefaultPlugins]?: DefaultPlugins[Name] | false;
+};
+
+export type BuiltinsWithOptionalParams = DefaultPlugins & {
+  'preset-default': {
+    floatPrecision?: number;
+    /**
+     * All default plugins can be customized or disabled here
+     * for example
+     * {
+     *   sortAttrs: { xmlnsOrder: "alphabetical" },
+     *   cleanupAttrs: false,
+     * }
+     */
+    overrides?: PresetDefaultOverrides;
+  };
+  cleanupListOfValues: {
+    floatPrecision?: number;
+    leadingZero?: boolean;
+    defaultPx?: boolean;
+    convertToPx?: boolean;
+  };
+  convertOneStopGradients: void;
+  convertStyleToAttrs: {
+    keepImportant?: boolean;
+  };
+  prefixIds: {
+    prefix?:
+      | boolean
+      | string
+      | ((node: XastElement, info: PluginInfo) => string);
+    delim?: string;
+    prefixIds?: boolean;
+    prefixClassNames?: boolean;
+  };
+  removeDimensions: void;
+  removeOffCanvasPaths: void;
+  removeRasterImages: void;
+  removeScriptElement: void;
+  removeStyleElement: void;
+  removeXlink: {
+    /**
+     * By default this plugin ignores legacy elements that were deprecated or
+     * removed in SVG 2. Set to true to force performing operations on those
+     * too.
+     *
+     * @default false
+     */
+    includeLegacy: boolean;
+  };
+  removeXMLNS: void;
+  reusePaths: void;
+};
+
+export type BuiltinsWithRequiredParams = {
+  addAttributesToSVGElement: {
+    attribute?: string | Record<string, null | string>;
+    attributes?: Array<string | Record<string, null | string>>;
+  };
+  addClassesToSVGElement: {
+    className?: string;
+    classNames?: string[];
+  };
+  removeAttributesBySelector: any;
+  removeAttrs: {
+    elemSeparator?: string;
+    preserveCurrentColor?: boolean;
+    attrs: string | string[];
+  };
+  removeElementsByAttr: {
+    id?: string | string[];
+    class?: string | string[];
+  };
+};
+
+type PluginsParams = BuiltinsWithOptionalParams & BuiltinsWithRequiredParams;
+
+export type Plugin<Name extends keyof PluginsParams> = PluginDef<
+  PluginsParams[Name]
+>;

backend/node_modules/svgo/plugins/prefixIds.js

@@ -0,0 +1,268 @@
+'use strict';
+
+/**
+ * @typedef {import('../lib/types.js').PluginInfo} PluginInfo
+ * @typedef {import('../lib/types').XastElement} XastElement
+ */
+
+const csstree = require('css-tree');
+const { referencesProps } = require('./_collections.js');
+
+exports.name = 'prefixIds';
+exports.description = 'prefix IDs';
+
+/**
+ * extract basename from path
+ * @type {(path: string) => string}
+ */
+const getBasename = (path) => {
+  // extract everything after latest slash or backslash
+  const matched = /[/\\]?([^/\\]+)$/.exec(path);
+  if (matched) {
+    return matched[1];
+  }
+  return '';
+};
+
+/**
+ * escapes a string for being used as ID
+ * @type {(string: string) => string}
+ */
+const escapeIdentifierName = (str) => {
+  return str.replace(/[. ]/g, '_');
+};
+
+/**
+ * @type {(string: string) => string}
+ */
+const unquote = (string) => {
+  if (
+    (string.startsWith('"') && string.endsWith('"')) ||
+    (string.startsWith("'") && string.endsWith("'"))
+  ) {
+    return string.slice(1, -1);
+  }
+  return string;
+};
+
+/**
+ * Prefix the given string, unless it already starts with the generated prefix.
+ *
+ * @param {(id: string) => string} prefixGenerator Function to generate a prefix.
+ * @param {string} body An arbitrary string.
+ * @returns {string} The given string with a prefix prepended to it.
+ */
+const prefixId = (prefixGenerator, body) => {
+  const prefix = prefixGenerator(body);
+  if (body.startsWith(prefix)) {
+    return body;
+  }
+  return prefix + body;
+};
+
+/**
+ * Insert the prefix in a reference string. A reference string is already
+ * prefixed with #, so the prefix is inserted after the first character.
+ *
+ * @param {(id: string) => string} prefixGenerator Function to generate a prefix.
+ * @param {string} reference An arbitrary string, should start with "#".
+ * @returns {?string} The given string with a prefix inserted, or null if the string did not start with "#".
+ */
+const prefixReference = (prefixGenerator, reference) => {
+  if (reference.startsWith('#')) {
+    return '#' + prefixId(prefixGenerator, reference.slice(1));
+  }
+  return null;
+};
+
+/**
+ * Generates a prefix for the given string.
+ *
+ * @param {string} body An arbitrary string.
+ * @param {XastElement} node XML node that the identifier belongs to.
+ * @param {PluginInfo} info
+ * @param {((node: XastElement, info: PluginInfo) => string)|string|boolean|undefined} prefixGenerator Some way of obtaining a prefix.
+ * @param {string} delim Content to insert between the prefix and original value.
+ * @param {Map<string, string>} history Map of previously generated prefixes to IDs.
+ * @returns {string} A generated prefix.
+ */
+const generatePrefix = (body, node, info, prefixGenerator, delim, history) => {
+  if (typeof prefixGenerator === 'function') {
+    let prefix = history.get(body);
+
+    if (prefix != null) {
+      return prefix;
+    }
+
+    prefix = prefixGenerator(node, info) + delim;
+    history.set(body, prefix);
+    return prefix;
+  }
+
+  if (typeof prefixGenerator === 'string') {
+    return prefixGenerator + delim;
+  }
+
+  if (prefixGenerator === false) {
+    return '';
+  }
+
+  if (info.path != null && info.path.length > 0) {
+    return escapeIdentifierName(getBasename(info.path)) + delim;
+  }
+
+  return 'prefix' + delim;
+};
+
+/**
+ * Prefixes identifiers
+ *
+ * @author strarsis <strarsis@gmail.com>
+ * @type {import('./plugins-types').Plugin<'prefixIds'>}
+ */
+exports.fn = (_root, params, info) => {
+  const {
+    delim = '__',
+    prefix,
+    prefixIds = true,
+    prefixClassNames = true,
+  } = params;
+
+  /** @type {Map<string, string>} */
+  const prefixMap = new Map();
+
+  return {
+    element: {
+      enter: (node) => {
+        /**
+         * @param {string} id A node identifier or class.
+         * @returns {string} Given string with a prefix inserted, or null if the string did not start with "#".
+         */
+        const prefixGenerator = (id) =>
+          generatePrefix(id, node, info, prefix, delim, prefixMap);
+
+        // prefix id/class selectors and url() references in styles
+        if (node.name === 'style') {
+          // skip empty <style/> elements
+          if (node.children.length === 0) {
+            return;
+          }
+
+          for (const child of node.children) {
+            if (child.type !== 'text' && child.type !== 'cdata') {
+              continue;
+            }
+
+            const cssText = child.value;
+            /** @type {?csstree.CssNode} */
+            let cssAst = null;
+            try {
+              cssAst = csstree.parse(cssText, {
+                parseValue: true,
+                parseCustomProperty: false,
+              });
+            } catch {
+              return;
+            }
+
+            csstree.walk(cssAst, (node) => {
+              if (
+                (prefixIds && node.type === 'IdSelector') ||
+                (prefixClassNames && node.type === 'ClassSelector')
+              ) {
+                node.name = prefixId(prefixGenerator, node.name);
+                return;
+              }
+              if (node.type === 'Url' && node.value.length > 0) {
+                const prefixed = prefixReference(
+                  prefixGenerator,
+                  unquote(node.value),
+                );
+                if (prefixed != null) {
+                  node.value = prefixed;
+                }
+              }
+            });
+
+            child.value = csstree.generate(cssAst);
+            return;
+          }
+        }
+
+        // prefix an ID attribute value
+        if (
+          prefixIds &&
+          node.attributes.id != null &&
+          node.attributes.id.length !== 0
+        ) {
+          node.attributes.id = prefixId(prefixGenerator, node.attributes.id);
+        }
+
+        // prefix a class attribute value
+        if (
+          prefixClassNames &&
+          node.attributes.class != null &&
+          node.attributes.class.length !== 0
+        ) {
+          node.attributes.class = node.attributes.class
+            .split(/\s+/)
+            .map((name) => prefixId(prefixGenerator, name))
+            .join(' ');
+        }
+
+        // prefix a href attribute value
+        // xlink:href is deprecated, must be still supported
+        for (const name of ['href', 'xlink:href']) {
+          if (
+            node.attributes[name] != null &&
+            node.attributes[name].length !== 0
+          ) {
+            const prefixed = prefixReference(
+              prefixGenerator,
+              node.attributes[name],
+            );
+            if (prefixed != null) {
+              node.attributes[name] = prefixed;
+            }
+          }
+        }
+
+        // prefix a URL attribute value
+        for (const name of referencesProps) {
+          if (
+            node.attributes[name] != null &&
+            node.attributes[name].length !== 0
+          ) {
+            node.attributes[name] = node.attributes[name].replace(
+              /\burl\((["'])?(#.+?)\1\)/gi,
+              (match, _, url) => {
+                const prefixed = prefixReference(prefixGenerator, url);
+                if (prefixed == null) {
+                  return match;
+                }
+                return `url(${prefixed})`;
+              },
+            );
+          }
+        }
+
+        // prefix begin/end attribute value
+        for (const name of ['begin', 'end']) {
+          if (
+            node.attributes[name] != null &&
+            node.attributes[name].length !== 0
+          ) {
+            const parts = node.attributes[name].split(/\s*;\s+/).map((val) => {
+              if (val.endsWith('.end') || val.endsWith('.start')) {
+                const [id, postfix] = val.split('.');
+                return `${prefixId(prefixGenerator, id)}.${postfix}`;
+              }
+              return val;
+            });
+            node.attributes[name] = parts.join('; ');
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/preset-default.js

@@ -0,0 +1,82 @@
+'use strict';
+
+const { createPreset } = require('../lib/svgo/plugins.js');
+
+const removeDoctype = require('./removeDoctype.js');
+const removeXMLProcInst = require('./removeXMLProcInst.js');
+const removeComments = require('./removeComments.js');
+const removeMetadata = require('./removeMetadata.js');
+const removeEditorsNSData = require('./removeEditorsNSData.js');
+const cleanupAttrs = require('./cleanupAttrs.js');
+const mergeStyles = require('./mergeStyles.js');
+const inlineStyles = require('./inlineStyles.js');
+const minifyStyles = require('./minifyStyles.js');
+const cleanupIds = require('./cleanupIds.js');
+const removeUselessDefs = require('./removeUselessDefs.js');
+const cleanupNumericValues = require('./cleanupNumericValues.js');
+const convertColors = require('./convertColors.js');
+const removeUnknownsAndDefaults = require('./removeUnknownsAndDefaults.js');
+const removeNonInheritableGroupAttrs = require('./removeNonInheritableGroupAttrs.js');
+const removeUselessStrokeAndFill = require('./removeUselessStrokeAndFill.js');
+const removeViewBox = require('./removeViewBox.js');
+const cleanupEnableBackground = require('./cleanupEnableBackground.js');
+const removeHiddenElems = require('./removeHiddenElems.js');
+const removeEmptyText = require('./removeEmptyText.js');
+const convertShapeToPath = require('./convertShapeToPath.js');
+const convertEllipseToCircle = require('./convertEllipseToCircle.js');
+const moveElemsAttrsToGroup = require('./moveElemsAttrsToGroup.js');
+const moveGroupAttrsToElems = require('./moveGroupAttrsToElems.js');
+const collapseGroups = require('./collapseGroups.js');
+const convertPathData = require('./convertPathData.js');
+const convertTransform = require('./convertTransform.js');
+const removeEmptyAttrs = require('./removeEmptyAttrs.js');
+const removeEmptyContainers = require('./removeEmptyContainers.js');
+const mergePaths = require('./mergePaths.js');
+const removeUnusedNS = require('./removeUnusedNS.js');
+const sortAttrs = require('./sortAttrs.js');
+const sortDefsChildren = require('./sortDefsChildren.js');
+const removeTitle = require('./removeTitle.js');
+const removeDesc = require('./removeDesc.js');
+
+const presetDefault = createPreset({
+  name: 'preset-default',
+  plugins: [
+    removeDoctype,
+    removeXMLProcInst,
+    removeComments,
+    removeMetadata,
+    removeEditorsNSData,
+    cleanupAttrs,
+    mergeStyles,
+    inlineStyles,
+    minifyStyles,
+    cleanupIds,
+    removeUselessDefs,
+    cleanupNumericValues,
+    convertColors,
+    removeUnknownsAndDefaults,
+    removeNonInheritableGroupAttrs,
+    removeUselessStrokeAndFill,
+    removeViewBox,
+    cleanupEnableBackground,
+    removeHiddenElems,
+    removeEmptyText,
+    convertShapeToPath,
+    convertEllipseToCircle,
+    moveElemsAttrsToGroup,
+    moveGroupAttrsToElems,
+    collapseGroups,
+    convertPathData,
+    convertTransform,
+    removeEmptyAttrs,
+    removeEmptyContainers,
+    mergePaths,
+    removeUnusedNS,
+    sortAttrs,
+    sortDefsChildren,
+    removeTitle,
+    removeDesc,
+  ],
+});
+
+module.exports = presetDefault;

backend/node_modules/svgo/plugins/removeAttributesBySelector.js

@@ -0,0 +1,97 @@
+'use strict';
+
+const { querySelectorAll } = require('../lib/xast.js');
+
+exports.name = 'removeAttributesBySelector';
+exports.description =
+  'removes attributes of elements that match a css selector';
+
+/**
+ * Removes attributes of elements that match a css selector.
+ *
+ * @example
+ * <caption>A selector removing a single attribute</caption>
+ * plugins: [
+ *   {
+ *     name: "removeAttributesBySelector",
+ *     params: {
+ *       selector: "[fill='#00ff00']"
+ *       attributes: "fill"
+ *     }
+ *   }
+ * ]
+ *
+ * <rect x="0" y="0" width="100" height="100" fill="#00ff00" stroke="#00ff00"/>
+ *   ↓
+ * <rect x="0" y="0" width="100" height="100" stroke="#00ff00"/>
+ *
+ * <caption>A selector removing multiple attributes</caption>
+ * plugins: [
+ *   {
+ *     name: "removeAttributesBySelector",
+ *     params: {
+ *       selector: "[fill='#00ff00']",
+ *       attributes: [
+ *         "fill",
+ *         "stroke"
+ *       ]
+ *     }
+ *   }
+ * ]
+ *
+ * <rect x="0" y="0" width="100" height="100" fill="#00ff00" stroke="#00ff00"/>
+ *   ↓
+ * <rect x="0" y="0" width="100" height="100"/>
+ *
+ * <caption>Multiple selectors removing attributes</caption>
+ * plugins: [
+ *   {
+ *     name: "removeAttributesBySelector",
+ *     params: {
+ *       selectors: [
+ *         {
+ *           selector: "[fill='#00ff00']",
+ *           attributes: "fill"
+ *         },
+ *         {
+ *           selector: "#remove",
+ *           attributes: [
+ *             "stroke",
+ *             "id"
+ *           ]
+ *         }
+ *       ]
+ *     }
+ *   }
+ * ]
+ *
+ * <rect x="0" y="0" width="100" height="100" fill="#00ff00" stroke="#00ff00"/>
+ *   ↓
+ * <rect x="0" y="0" width="100" height="100"/>
+ *
+ * @link https://developer.mozilla.org/docs/Web/CSS/CSS_Selectors|MDN CSS Selectors
+ *
+ * @author Bradley Mease
+ *
+ * @type {import('./plugins-types').Plugin<'removeAttributesBySelector'>}
+ */
+exports.fn = (root, params) => {
+  const selectors = Array.isArray(params.selectors)
+    ? params.selectors
+    : [params];
+  for (const { selector, attributes } of selectors) {
+    const nodes = querySelectorAll(root, selector);
+    for (const node of nodes) {
+      if (node.type === 'element') {
+        if (Array.isArray(attributes)) {
+          for (const name of attributes) {
+            delete node.attributes[name];
+          }
+        } else {
+          delete node.attributes[attributes];
+        }
+      }
+    }
+  }
+  return {};
+};

backend/node_modules/svgo/plugins/removeAttrs.js

@@ -0,0 +1,151 @@
+'use strict';
+
+exports.name = 'removeAttrs';
+exports.description = 'removes specified attributes';
+
+const DEFAULT_SEPARATOR = ':';
+const ENOATTRS = `Warning: The plugin "removeAttrs" requires the "attrs" parameter.
+It should have a pattern to remove, otherwise the plugin is a noop.
+Config example:
+
+plugins: [
+  {
+    name: "removeAttrs",
+    params: {
+      attrs: "(fill|stroke)"
+    }
+  }
+]
+`;
+
+/**
+ * Remove attributes
+ *
+ * @example elemSeparator
+ *   format: string
+ *
+ * @example preserveCurrentColor
+ *   format: boolean
+ *
+ * @example attrs:
+ *
+ *   format: [ element* : attribute* : value* ]
+ *
+ *   element   : regexp (wrapped into ^...$), single * or omitted > all elements (must be present when value is used)
+ *   attribute : regexp (wrapped into ^...$)
+ *   value     : regexp (wrapped into ^...$), single * or omitted > all values
+ *
+ *   examples:
+ *
+ *     > basic: remove fill attribute
+ *     ---
+ *     removeAttrs:
+ *       attrs: 'fill'
+ *
+ *     > remove fill attribute on path element
+ *     ---
+ *       attrs: 'path:fill'
+ *
+ *     > remove fill attribute on path element where value is none
+ *     ---
+ *       attrs: 'path:fill:none'
+ *
+ *
+ *     > remove all fill and stroke attribute
+ *     ---
+ *       attrs:
+ *         - 'fill'
+ *         - 'stroke'
+ *
+ *     [is same as]
+ *
+ *       attrs: '(fill|stroke)'
+ *
+ *     [is same as]
+ *
+ *       attrs: '*:(fill|stroke)'
+ *
+ *     [is same as]
+ *
+ *       attrs: '.*:(fill|stroke)'
+ *
+ *     [is same as]
+ *
+ *       attrs: '.*:(fill|stroke):.*'
+ *
+ *
+ *     > remove all stroke related attributes
+ *     ----
+ *     attrs: 'stroke.*'
+ *
+ *
+ * @author Benny Schudel
+ *
+ * @type {import('./plugins-types').Plugin<'removeAttrs'>}
+ */
+exports.fn = (root, params) => {
+  if (typeof params.attrs == 'undefined') {
+    console.warn(ENOATTRS);
+    return null;
+  }
+
+  const elemSeparator =
+    typeof params.elemSeparator == 'string'
+      ? params.elemSeparator
+      : DEFAULT_SEPARATOR;
+  const preserveCurrentColor =
+    typeof params.preserveCurrentColor == 'boolean'
+      ? params.preserveCurrentColor
+      : false;
+  const attrs = Array.isArray(params.attrs) ? params.attrs : [params.attrs];
+
+  return {
+    element: {
+      enter: (node) => {
+        for (let pattern of attrs) {
+          // if no element separators (:), assume it's attribute name, and apply to all elements *regardless of value*
+          if (!pattern.includes(elemSeparator)) {
+            pattern = ['.*', pattern, '.*'].join(elemSeparator);
+            // if only 1 separator, assume it's element and attribute name, and apply regardless of attribute value
+          } else if (pattern.split(elemSeparator).length < 3) {
+            pattern = [pattern, '.*'].join(elemSeparator);
+          }
+
+          // create regexps for element, attribute name, and attribute value
+          const list = pattern.split(elemSeparator).map((value) => {
+            // adjust single * to match anything
+            if (value === '*') {
+              value = '.*';
+            }
+            return new RegExp(['^', value, '$'].join(''), 'i');
+          });
+
+          // matches element
+          if (list[0].test(node.name)) {
+            // loop attributes
+            for (const [name, value] of Object.entries(node.attributes)) {
+              const isFillCurrentColor =
+                preserveCurrentColor &&
+                name == 'fill' &&
+                value == 'currentColor';
+              const isStrokeCurrentColor =
+                preserveCurrentColor &&
+                name == 'stroke' &&
+                value == 'currentColor';
+              if (
+                !isFillCurrentColor &&
+                !isStrokeCurrentColor &&
+                // matches attribute name
+                list[1].test(name) &&
+                // matches attribute value
+                list[2].test(value)
+              ) {
+                delete node.attributes[name];
+              }
+            }
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeComments.js

@@ -0,0 +1,51 @@
+'use strict';
+
+const { detachNodeFromParent } = require('../lib/xast.js');
+
+exports.name = 'removeComments';
+exports.description = 'removes comments';
+
+/**
+ * If a comment matches one of the following patterns, it will be
+ * preserved by default. Particularly for copyright/license information.
+ */
+const DEFAULT_PRESERVE_PATTERNS = [/^!/];
+
+/**
+ * Remove comments.
+ *
+ * @example
+ * <!-- Generator: Adobe Illustrator 15.0.0, SVG Export
+ * Plug-In . SVG Version: 6.00 Build 0)  -->
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'removeComments'>}
+ */
+exports.fn = (_root, params) => {
+  const { preservePatterns = DEFAULT_PRESERVE_PATTERNS } = params;
+
+  return {
+    comment: {
+      enter: (node, parentNode) => {
+        if (preservePatterns) {
+          if (!Array.isArray(preservePatterns)) {
+            throw Error(
+              `Expected array in removeComments preservePatterns parameter but received ${preservePatterns}`,
+            );
+          }
+
+          const matches = preservePatterns.some((pattern) => {
+            return new RegExp(pattern).test(node.value);
+          });
+
+          if (matches) {
+            return;
+          }
+        }
+
+        detachNodeFromParent(node, parentNode);
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeDesc.js

@@ -0,0 +1,39 @@
+'use strict';
+
+const { detachNodeFromParent } = require('../lib/xast.js');
+
+exports.name = 'removeDesc';
+exports.description = 'removes <desc>';
+
+const standardDescs = /^(Created with|Created using)/;
+
+/**
+ * Removes <desc>.
+ * Removes only standard editors content or empty elements 'cause it can be used for accessibility.
+ * Enable parameter 'removeAny' to remove any description.
+ *
+ * https://developer.mozilla.org/docs/Web/SVG/Element/desc
+ *
+ * @author Daniel Wabyick
+ *
+ * @type {import('./plugins-types').Plugin<'removeDesc'>}
+ */
+exports.fn = (root, params) => {
+  const { removeAny = false } = params;
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        if (node.name === 'desc') {
+          if (
+            removeAny ||
+            node.children.length === 0 ||
+            (node.children[0].type === 'text' &&
+              standardDescs.test(node.children[0].value))
+          ) {
+            detachNodeFromParent(node, parentNode);
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeDimensions.js

@@ -0,0 +1,43 @@
+'use strict';
+
+exports.name = 'removeDimensions';
+exports.description =
+  'removes width and height in presence of viewBox (opposite to removeViewBox, disable it first)';
+
+/**
+ * Remove width/height attributes and add the viewBox attribute if it's missing
+ *
+ * @example
+ * <svg width="100" height="50" />
+ *   ↓
+ * <svg viewBox="0 0 100 50" />
+ *
+ * @author Benny Schudel
+ *
+ * @type {import('./plugins-types').Plugin<'removeDimensions'>}
+ */
+exports.fn = () => {
+  return {
+    element: {
+      enter: (node) => {
+        if (node.name === 'svg') {
+          if (node.attributes.viewBox != null) {
+            delete node.attributes.width;
+            delete node.attributes.height;
+          } else if (
+            node.attributes.width != null &&
+            node.attributes.height != null &&
+            Number.isNaN(Number(node.attributes.width)) === false &&
+            Number.isNaN(Number(node.attributes.height)) === false
+          ) {
+            const width = Number(node.attributes.width);
+            const height = Number(node.attributes.height);
+            node.attributes.viewBox = `0 0 ${width} ${height}`;
+            delete node.attributes.width;
+            delete node.attributes.height;
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeDoctype.js

@@ -0,0 +1,40 @@
+'use strict';
+
+const { detachNodeFromParent } = require('../lib/xast.js');
+
+exports.name = 'removeDoctype';
+exports.description = 'removes doctype declaration';
+
+/**
+ * Remove DOCTYPE declaration.
+ *
+ * "Unfortunately the SVG DTDs are a source of so many
+ * issues that the SVG WG has decided not to write one
+ * for the upcoming SVG 1.2 standard. In fact SVG WG
+ * members are even telling people not to use a DOCTYPE
+ * declaration in SVG 1.0 and 1.1 documents"
+ * https://jwatt.org/svg/authoring/#doctype-declaration
+ *
+ * @example
+ * <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
+ * q"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+ *
+ * @example
+ * <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
+ * "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" [
+ *     <!-- an internal subset can be embedded here -->
+ * ]>
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'removeDoctype'>}
+ */
+exports.fn = () => {
+  return {
+    doctype: {
+      enter: (node, parentNode) => {
+        detachNodeFromParent(node, parentNode);
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeEditorsNSData.js

@@ -0,0 +1,64 @@
+'use strict';
+
+const { detachNodeFromParent } = require('../lib/xast.js');
+const { editorNamespaces } = require('./_collections.js');
+
+exports.name = 'removeEditorsNSData';
+exports.description = 'removes editors namespaces, elements and attributes';
+
+/**
+ * Remove editors namespaces, elements and attributes.
+ *
+ * @example
+ * <svg xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd">
+ * <sodipodi:namedview/>
+ * <path sodipodi:nodetypes="cccc"/>
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'removeEditorsNSData'>}
+ */
+exports.fn = (_root, params) => {
+  let namespaces = [...editorNamespaces];
+  if (Array.isArray(params.additionalNamespaces)) {
+    namespaces = [...editorNamespaces, ...params.additionalNamespaces];
+  }
+  /**
+   * @type {string[]}
+   */
+  const prefixes = [];
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        // collect namespace prefixes from svg element
+        if (node.name === 'svg') {
+          for (const [name, value] of Object.entries(node.attributes)) {
+            if (name.startsWith('xmlns:') && namespaces.includes(value)) {
+              prefixes.push(name.slice('xmlns:'.length));
+              // <svg xmlns:sodipodi="">
+              delete node.attributes[name];
+            }
+          }
+        }
+        // remove editor attributes, for example
+        // <* sodipodi:*="">
+        for (const name of Object.keys(node.attributes)) {
+          if (name.includes(':')) {
+            const [prefix] = name.split(':');
+            if (prefixes.includes(prefix)) {
+              delete node.attributes[name];
+            }
+          }
+        }
+        // remove editor elements, for example
+        // <sodipodi:*>
+        if (node.name.includes(':')) {
+          const [prefix] = node.name.split(':');
+          if (prefixes.includes(prefix)) {
+            detachNodeFromParent(node, parentNode);
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeElementsByAttr.js

@@ -0,0 +1,73 @@
+'use strict';
+
+const { detachNodeFromParent } = require('../lib/xast.js');
+
+exports.name = 'removeElementsByAttr';
+exports.description =
+  'removes arbitrary elements by ID or className (disabled by default)';
+
+/**
+ * Remove arbitrary SVG elements by ID or className.
+ *
+ * @example id
+ *     > single: remove element with ID of `elementID`
+ *     ---
+ *     removeElementsByAttr:
+ *       id: 'elementID'
+ *
+ *     > list: remove multiple elements by ID
+ *     ---
+ *     removeElementsByAttr:
+ *       id:
+ *         - 'elementID'
+ *         - 'anotherID'
+ *
+ * @example class
+ *     > single: remove all elements with class of `elementClass`
+ *     ---
+ *     removeElementsByAttr:
+ *       class: 'elementClass'
+ *
+ *     > list: remove all elements with class of `elementClass` or `anotherClass`
+ *     ---
+ *     removeElementsByAttr:
+ *       class:
+ *         - 'elementClass'
+ *         - 'anotherClass'
+ *
+ * @author Eli Dupuis (@elidupuis)
+ *
+ * @type {import('./plugins-types').Plugin<'removeElementsByAttr'>}
+ */
+exports.fn = (root, params) => {
+  const ids =
+    params.id == null ? [] : Array.isArray(params.id) ? params.id : [params.id];
+  const classes =
+    params.class == null
+      ? []
+      : Array.isArray(params.class)
+        ? params.class
+        : [params.class];
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        // remove element if it's `id` matches configured `id` params
+        if (node.attributes.id != null && ids.length !== 0) {
+          if (ids.includes(node.attributes.id)) {
+            detachNodeFromParent(node, parentNode);
+          }
+        }
+        // remove element if it's `class` contains any of the configured `class` params
+        if (node.attributes.class && classes.length !== 0) {
+          const classList = node.attributes.class.split(' ');
+          for (const item of classes) {
+            if (classList.includes(item)) {
+              detachNodeFromParent(node, parentNode);
+              break;
+            }
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeEmptyAttrs.js

@@ -0,0 +1,31 @@
+'use strict';
+
+const { attrsGroups } = require('./_collections.js');
+
+exports.name = 'removeEmptyAttrs';
+exports.description = 'removes empty attributes';
+
+/**
+ * Remove attributes with empty values.
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'removeEmptyAttrs'>}
+ */
+exports.fn = () => {
+  return {
+    element: {
+      enter: (node) => {
+        for (const [name, value] of Object.entries(node.attributes)) {
+          if (
+            value === '' &&
+            // empty conditional processing attributes prevents elements from rendering
+            !attrsGroups.conditionalProcessing.has(name)
+          ) {
+            delete node.attributes[name];
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeEmptyContainers.js

@@ -0,0 +1,59 @@
+'use strict';
+
+const { detachNodeFromParent } = require('../lib/xast.js');
+const { elemsGroups } = require('./_collections.js');
+
+exports.name = 'removeEmptyContainers';
+exports.description = 'removes empty container elements';
+
+/**
+ * Remove empty containers.
+ *
+ * @see https://www.w3.org/TR/SVG11/intro.html#TermContainerElement
+ *
+ * @example
+ * <defs/>
+ *
+ * @example
+ * <g><marker><a/></marker></g>
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'removeEmptyContainers'>}
+ */
+exports.fn = () => {
+  return {
+    element: {
+      exit: (node, parentNode) => {
+        // remove only empty non-svg containers
+        if (
+          node.name === 'svg' ||
+          !elemsGroups.container.has(node.name) ||
+          node.children.length !== 0
+        ) {
+          return;
+        }
+        // empty patterns may contain reusable configuration
+        if (
+          node.name === 'pattern' &&
+          Object.keys(node.attributes).length !== 0
+        ) {
+          return;
+        }
+        // The <g> may not have content, but the filter may cause a rectangle
+        // to be created and filled with pattern.
+        if (node.name === 'g' && node.attributes.filter != null) {
+          return;
+        }
+        // empty <mask> hides masked element
+        if (node.name === 'mask' && node.attributes.id != null) {
+          return;
+        }
+        if (parentNode.type === 'element' && parentNode.name === 'switch') {
+          return;
+        }
+        detachNodeFromParent(node, parentNode);
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeEmptyText.js

@@ -0,0 +1,51 @@
+'use strict';
+
+const { detachNodeFromParent } = require('../lib/xast.js');
+
+exports.name = 'removeEmptyText';
+exports.description = 'removes empty <text> elements';
+
+/**
+ * Remove empty Text elements.
+ *
+ * @see https://www.w3.org/TR/SVG11/text.html
+ *
+ * @example
+ * Remove empty text element:
+ * <text/>
+ *
+ * Remove empty tspan element:
+ * <tspan/>
+ *
+ * Remove tref with empty xlink:href attribute:
+ * <tref xlink:href=""/>
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'removeEmptyText'>}
+ */
+exports.fn = (root, params) => {
+  const { text = true, tspan = true, tref = true } = params;
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        // Remove empty text element
+        if (text && node.name === 'text' && node.children.length === 0) {
+          detachNodeFromParent(node, parentNode);
+        }
+        // Remove empty tspan element
+        if (tspan && node.name === 'tspan' && node.children.length === 0) {
+          detachNodeFromParent(node, parentNode);
+        }
+        // Remove tref with empty xlink:href attribute
+        if (
+          tref &&
+          node.name === 'tref' &&
+          node.attributes['xlink:href'] == null
+        ) {
+          detachNodeFromParent(node, parentNode);
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeHiddenElems.js

@@ -0,0 +1,440 @@
+'use strict';
+
+/**
+ * @typedef {import('../lib/types').XastChild} XastChild
+ * @typedef {import('../lib/types').XastElement} XastElement
+ * @typedef {import('../lib/types').XastParent} XastParent
+ */
+
+const { elemsGroups } = require('./_collections.js');
+const {
+  visit,
+  visitSkip,
+  querySelector,
+  detachNodeFromParent,
+} = require('../lib/xast.js');
+const { collectStylesheet, computeStyle } = require('../lib/style.js');
+const { parsePathData } = require('../lib/path.js');
+const { hasScripts, findReferences } = require('../lib/svgo/tools.js');
+
+const nonRendering = elemsGroups.nonRendering;
+
+exports.name = 'removeHiddenElems';
+exports.description =
+  'removes hidden elements (zero sized, with absent attributes)';
+
+/**
+ * Remove hidden elements with disabled rendering:
+ * - display="none"
+ * - opacity="0"
+ * - circle with zero radius
+ * - ellipse with zero x-axis or y-axis radius
+ * - rectangle with zero width or height
+ * - pattern with zero width or height
+ * - image with zero width or height
+ * - path with empty data
+ * - polyline with empty points
+ * - polygon with empty points
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'removeHiddenElems'>}
+ */
+exports.fn = (root, params) => {
+  const {
+    isHidden = true,
+    displayNone = true,
+    opacity0 = true,
+    circleR0 = true,
+    ellipseRX0 = true,
+    ellipseRY0 = true,
+    rectWidth0 = true,
+    rectHeight0 = true,
+    patternWidth0 = true,
+    patternHeight0 = true,
+    imageWidth0 = true,
+    imageHeight0 = true,
+    pathEmptyD = true,
+    polylineEmptyPoints = true,
+    polygonEmptyPoints = true,
+  } = params;
+  const stylesheet = collectStylesheet(root);
+
+  /**
+   * Skip non-rendered nodes initially, and only detach if they have no ID, or
+   * their ID is not referenced by another node.
+   *
+   * @type {Map<XastElement, XastParent>}
+   */
+  const nonRenderedNodes = new Map();
+
+  /**
+   * IDs for removed hidden definitions.
+   *
+   * @type {Set<string>}
+   */
+  const removedDefIds = new Set();
+
+  /**
+   * @type {Map<XastElement, XastParent>}
+   */
+  const allDefs = new Map();
+
+  /** @type {Set<string>} */
+  const allReferences = new Set();
+
+  /**
+   * @type {Map<string, Array<{ node: XastElement, parentNode: XastParent }>>}
+   */
+  const referencesById = new Map();
+
+  /**
+   * If styles are present, we can't be sure if a definition is unused or not
+   */
+  let deoptimized = false;
+
+  /**
+   * @param {XastChild} node
+   * @param {XastParent} parentNode
+   */
+  function removeElement(node, parentNode) {
+    if (
+      node.type === 'element' &&
+      node.attributes.id != null &&
+      parentNode.type === 'element' &&
+      parentNode.name === 'defs'
+    ) {
+      removedDefIds.add(node.attributes.id);
+    }
+
+    detachNodeFromParent(node, parentNode);
+  }
+
+  visit(root, {
+    element: {
+      enter: (node, parentNode) => {
+        // transparent non-rendering elements still apply where referenced
+        if (nonRendering.has(node.name)) {
+          if (node.attributes.id == null) {
+            detachNodeFromParent(node, parentNode);
+            return visitSkip;
+          }
+
+          nonRenderedNodes.set(node, parentNode);
+          return visitSkip;
+        }
+        const computedStyle = computeStyle(stylesheet, node);
+        // opacity="0"
+        //
+        // https://www.w3.org/TR/SVG11/masking.html#ObjectAndGroupOpacityProperties
+        if (
+          opacity0 &&
+          computedStyle.opacity &&
+          computedStyle.opacity.type === 'static' &&
+          computedStyle.opacity.value === '0'
+        ) {
+          removeElement(node, parentNode);
+        }
+      },
+    },
+  });
+
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        if (
+          (node.name === 'style' && node.children.length !== 0) ||
+          hasScripts(node)
+        ) {
+          deoptimized = true;
+          return;
+        }
+
+        if (node.name === 'defs') {
+          allDefs.set(node, parentNode);
+        }
+
+        if (node.name === 'use') {
+          for (const attr of Object.keys(node.attributes)) {
+            if (attr !== 'href' && !attr.endsWith(':href')) continue;
+            const value = node.attributes[attr];
+            const id = value.slice(1);
+
+            let refs = referencesById.get(id);
+            if (!refs) {
+              refs = [];
+              referencesById.set(id, refs);
+            }
+            refs.push({ node, parentNode });
+          }
+        }
+
+        // Removes hidden elements
+        // https://www.w3schools.com/cssref/pr_class_visibility.asp
+        const computedStyle = computeStyle(stylesheet, node);
+        if (
+          isHidden &&
+          computedStyle.visibility &&
+          computedStyle.visibility.type === 'static' &&
+          computedStyle.visibility.value === 'hidden' &&
+          // keep if any descendant enables visibility
+          querySelector(node, '[visibility=visible]') == null
+        ) {
+          removeElement(node, parentNode);
+          return;
+        }
+
+        // display="none"
+        //
+        // https://www.w3.org/TR/SVG11/painting.html#DisplayProperty
+        // "A value of display: none indicates that the given element
+        // and its children shall not be rendered directly"
+        if (
+          displayNone &&
+          computedStyle.display &&
+          computedStyle.display.type === 'static' &&
+          computedStyle.display.value === 'none' &&
+          // markers with display: none still rendered
+          node.name !== 'marker'
+        ) {
+          removeElement(node, parentNode);
+          return;
+        }
+
+        // Circles with zero radius
+        //
+        // https://www.w3.org/TR/SVG11/shapes.html#CircleElementRAttribute
+        // "A value of zero disables rendering of the element"
+        //
+        // <circle r="0">
+        if (
+          circleR0 &&
+          node.name === 'circle' &&
+          node.children.length === 0 &&
+          node.attributes.r === '0'
+        ) {
+          removeElement(node, parentNode);
+          return;
+        }
+
+        // Ellipse with zero x-axis radius
+        //
+        // https://www.w3.org/TR/SVG11/shapes.html#EllipseElementRXAttribute
+        // "A value of zero disables rendering of the element"
+        //
+        // <ellipse rx="0">
+        if (
+          ellipseRX0 &&
+          node.name === 'ellipse' &&
+          node.children.length === 0 &&
+          node.attributes.rx === '0'
+        ) {
+          removeElement(node, parentNode);
+          return;
+        }
+
+        // Ellipse with zero y-axis radius
+        //
+        // https://www.w3.org/TR/SVG11/shapes.html#EllipseElementRYAttribute
+        // "A value of zero disables rendering of the element"
+        //
+        // <ellipse ry="0">
+        if (
+          ellipseRY0 &&
+          node.name === 'ellipse' &&
+          node.children.length === 0 &&
+          node.attributes.ry === '0'
+        ) {
+          removeElement(node, parentNode);
+          return;
+        }
+
+        // Rectangle with zero width
+        //
+        // https://www.w3.org/TR/SVG11/shapes.html#RectElementWidthAttribute
+        // "A value of zero disables rendering of the element"
+        //
+        // <rect width="0">
+        if (
+          rectWidth0 &&
+          node.name === 'rect' &&
+          node.children.length === 0 &&
+          node.attributes.width === '0'
+        ) {
+          removeElement(node, parentNode);
+          return;
+        }
+
+        // Rectangle with zero height
+        //
+        // https://www.w3.org/TR/SVG11/shapes.html#RectElementHeightAttribute
+        // "A value of zero disables rendering of the element"
+        //
+        // <rect height="0">
+        if (
+          rectHeight0 &&
+          rectWidth0 &&
+          node.name === 'rect' &&
+          node.children.length === 0 &&
+          node.attributes.height === '0'
+        ) {
+          removeElement(node, parentNode);
+          return;
+        }
+
+        // Pattern with zero width
+        //
+        // https://www.w3.org/TR/SVG11/pservers.html#PatternElementWidthAttribute
+        // "A value of zero disables rendering of the element (i.e., no paint is applied)"
+        //
+        // <pattern width="0">
+        if (
+          patternWidth0 &&
+          node.name === 'pattern' &&
+          node.attributes.width === '0'
+        ) {
+          removeElement(node, parentNode);
+          return;
+        }
+
+        // Pattern with zero height
+        //
+        // https://www.w3.org/TR/SVG11/pservers.html#PatternElementHeightAttribute
+        // "A value of zero disables rendering of the element (i.e., no paint is applied)"
+        //
+        // <pattern height="0">
+        if (
+          patternHeight0 &&
+          node.name === 'pattern' &&
+          node.attributes.height === '0'
+        ) {
+          removeElement(node, parentNode);
+          return;
+        }
+
+        // Image with zero width
+        //
+        // https://www.w3.org/TR/SVG11/struct.html#ImageElementWidthAttribute
+        // "A value of zero disables rendering of the element"
+        //
+        // <image width="0">
+        if (
+          imageWidth0 &&
+          node.name === 'image' &&
+          node.attributes.width === '0'
+        ) {
+          removeElement(node, parentNode);
+          return;
+        }
+
+        // Image with zero height
+        //
+        // https://www.w3.org/TR/SVG11/struct.html#ImageElementHeightAttribute
+        // "A value of zero disables rendering of the element"
+        //
+        // <image height="0">
+        if (
+          imageHeight0 &&
+          node.name === 'image' &&
+          node.attributes.height === '0'
+        ) {
+          removeElement(node, parentNode);
+          return;
+        }
+
+        // Path with empty data
+        //
+        // https://www.w3.org/TR/SVG11/paths.html#DAttribute
+        //
+        // <path d=""/>
+        if (pathEmptyD && node.name === 'path') {
+          if (node.attributes.d == null) {
+            removeElement(node, parentNode);
+            return;
+          }
+          const pathData = parsePathData(node.attributes.d);
+          if (pathData.length === 0) {
+            removeElement(node, parentNode);
+            return;
+          }
+          // keep single point paths for markers
+          if (
+            pathData.length === 1 &&
+            computedStyle['marker-start'] == null &&
+            computedStyle['marker-end'] == null
+          ) {
+            removeElement(node, parentNode);
+            return;
+          }
+        }
+
+        // Polyline with empty points
+        //
+        // https://www.w3.org/TR/SVG11/shapes.html#PolylineElementPointsAttribute
+        //
+        // <polyline points="">
+        if (
+          polylineEmptyPoints &&
+          node.name === 'polyline' &&
+          node.attributes.points == null
+        ) {
+          removeElement(node, parentNode);
+          return;
+        }
+
+        // Polygon with empty points
+        //
+        // https://www.w3.org/TR/SVG11/shapes.html#PolygonElementPointsAttribute
+        //
+        // <polygon points="">
+        if (
+          polygonEmptyPoints &&
+          node.name === 'polygon' &&
+          node.attributes.points == null
+        ) {
+          removeElement(node, parentNode);
+          return;
+        }
+
+        for (const [name, value] of Object.entries(node.attributes)) {
+          const ids = findReferences(name, value);
+
+          for (const id of ids) {
+            allReferences.add(id);
+          }
+        }
+      },
+    },
+    root: {
+      exit: () => {
+        for (const id of removedDefIds) {
+          const refs = referencesById.get(id);
+          if (refs) {
+            for (const { node, parentNode } of refs) {
+              detachNodeFromParent(node, parentNode);
+            }
+          }
+        }
+
+        if (!deoptimized) {
+          for (const [
+            nonRenderedNode,
+            nonRenderedParent,
+          ] of nonRenderedNodes.entries()) {
+            const id = nonRenderedNode.attributes.id;
+
+            if (!allReferences.has(id)) {
+              detachNodeFromParent(nonRenderedNode, nonRenderedParent);
+            }
+          }
+        }
+
+        for (const [node, parentNode] of allDefs.entries()) {
+          if (node.children.length === 0) {
+            detachNodeFromParent(node, parentNode);
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeMetadata.js

@@ -0,0 +1,27 @@
+'use strict';
+
+const { detachNodeFromParent } = require('../lib/xast.js');
+
+exports.name = 'removeMetadata';
+exports.description = 'removes <metadata>';
+
+/**
+ * Remove <metadata>.
+ *
+ * https://www.w3.org/TR/SVG11/metadata.html
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'removeMetadata'>}
+ */
+exports.fn = () => {
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        if (node.name === 'metadata') {
+          detachNodeFromParent(node, parentNode);
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeNonInheritableGroupAttrs.js

@@ -0,0 +1,38 @@
+'use strict';
+
+const {
+  inheritableAttrs,
+  attrsGroups,
+  presentationNonInheritableGroupAttrs,
+} = require('./_collections');
+
+exports.name = 'removeNonInheritableGroupAttrs';
+exports.description =
+  'removes non-inheritable group’s presentational attributes';
+
+/**
+ * Remove non-inheritable group's "presentation" attributes.
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'removeNonInheritableGroupAttrs'>}
+ */
+exports.fn = () => {
+  return {
+    element: {
+      enter: (node) => {
+        if (node.name === 'g') {
+          for (const name of Object.keys(node.attributes)) {
+            if (
+              attrsGroups.presentation.has(name) &&
+              !inheritableAttrs.has(name) &&
+              !presentationNonInheritableGroupAttrs.has(name)
+            ) {
+              delete node.attributes[name];
+            }
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeOffCanvasPaths.js

@@ -0,0 +1,136 @@
+'use strict';
+
+/**
+ * @typedef {import('../lib/types').PathDataItem} PathDataItem
+ */
+
+const { visitSkip, detachNodeFromParent } = require('../lib/xast.js');
+const { parsePathData } = require('../lib/path.js');
+const { intersects } = require('./_path.js');
+
+exports.name = 'removeOffCanvasPaths';
+exports.description =
+  'removes elements that are drawn outside of the viewbox (disabled by default)';
+
+/**
+ * Remove elements that are drawn outside of the viewbox.
+ *
+ * @author JoshyPHP
+ *
+ * @type {import('./plugins-types').Plugin<'removeOffCanvasPaths'>}
+ */
+exports.fn = () => {
+  /**
+   * @type {?{
+   *   top: number,
+   *   right: number,
+   *   bottom: number,
+   *   left: number,
+   *   width: number,
+   *   height: number
+   * }}
+   */
+  let viewBoxData = null;
+
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        if (node.name === 'svg' && parentNode.type === 'root') {
+          let viewBox = '';
+          // find viewbox
+          if (node.attributes.viewBox != null) {
+            // remove commas and plus signs, normalize and trim whitespace
+            viewBox = node.attributes.viewBox;
+          } else if (
+            node.attributes.height != null &&
+            node.attributes.width != null
+          ) {
+            viewBox = `0 0 ${node.attributes.width} ${node.attributes.height}`;
+          }
+
+          // parse viewbox
+          // remove commas and plus signs, normalize and trim whitespace
+          viewBox = viewBox
+            .replace(/[,+]|px/g, ' ')
+            .replace(/\s+/g, ' ')
+            .replace(/^\s*|\s*$/g, '');
+          // ensure that the dimensions are 4 values separated by space
+          const m =
+            /^(-?\d*\.?\d+) (-?\d*\.?\d+) (\d*\.?\d+) (\d*\.?\d+)$/.exec(
+              viewBox,
+            );
+          if (m == null) {
+            return;
+          }
+          const left = Number.parseFloat(m[1]);
+          const top = Number.parseFloat(m[2]);
+          const width = Number.parseFloat(m[3]);
+          const height = Number.parseFloat(m[4]);
+
+          // store the viewBox boundaries
+          viewBoxData = {
+            left,
+            top,
+            right: left + width,
+            bottom: top + height,
+            width,
+            height,
+          };
+        }
+
+        // consider that any item with a transform attribute is visible
+        if (node.attributes.transform != null) {
+          return visitSkip;
+        }
+
+        if (
+          node.name === 'path' &&
+          node.attributes.d != null &&
+          viewBoxData != null
+        ) {
+          const pathData = parsePathData(node.attributes.d);
+
+          // consider that a M command within the viewBox is visible
+          let visible = false;
+          for (const pathDataItem of pathData) {
+            if (pathDataItem.command === 'M') {
+              const [x, y] = pathDataItem.args;
+              if (
+                x >= viewBoxData.left &&
+                x <= viewBoxData.right &&
+                y >= viewBoxData.top &&
+                y <= viewBoxData.bottom
+              ) {
+                visible = true;
+              }
+            }
+          }
+          if (visible) {
+            return;
+          }
+
+          if (pathData.length === 2) {
+            // close the path too short for intersects()
+            pathData.push({ command: 'z', args: [] });
+          }
+
+          const { left, top, width, height } = viewBoxData;
+          /**
+           * @type {PathDataItem[]}
+           */
+          const viewBoxPathData = [
+            { command: 'M', args: [left, top] },
+            { command: 'h', args: [width] },
+            { command: 'v', args: [height] },
+            { command: 'H', args: [left] },
+            { command: 'z', args: [] },
+          ];
+
+          if (intersects(viewBoxPathData, pathData) === false) {
+            detachNodeFromParent(node, parentNode);
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeRasterImages.js

@@ -0,0 +1,31 @@
+'use strict';
+
+const { detachNodeFromParent } = require('../lib/xast.js');
+
+exports.name = 'removeRasterImages';
+exports.description = 'removes raster images (disabled by default)';
+
+/**
+ * Remove raster images references in <image>.
+ *
+ * @see https://bugs.webkit.org/show_bug.cgi?id=63548
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'removeRasterImages'>}
+ */
+exports.fn = () => {
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        if (
+          node.name === 'image' &&
+          node.attributes['xlink:href'] != null &&
+          /(\.|image\/)(jpe?g|png|gif)/.test(node.attributes['xlink:href'])
+        ) {
+          detachNodeFromParent(node, parentNode);
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeScriptElement.js

@@ -0,0 +1,70 @@
+'use strict';
+
+const { detachNodeFromParent } = require('../lib/xast.js');
+const { attrsGroups } = require('./_collections.js');
+
+exports.name = 'removeScriptElement';
+exports.description = 'removes scripts (disabled by default)';
+
+/** Union of all event attributes. */
+const eventAttrs = [
+  ...attrsGroups.animationEvent,
+  ...attrsGroups.documentEvent,
+  ...attrsGroups.documentElementEvent,
+  ...attrsGroups.globalEvent,
+  ...attrsGroups.graphicalEvent,
+];
+
+/**
+ * Remove scripts.
+ *
+ * https://www.w3.org/TR/SVG11/script.html
+ *
+ * @author Patrick Klingemann
+ * @type {import('./plugins-types').Plugin<'removeScriptElement'>}
+ */
+exports.fn = () => {
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        if (node.name === 'script') {
+          detachNodeFromParent(node, parentNode);
+          return;
+        }
+
+        for (const attr of eventAttrs) {
+          if (node.attributes[attr] != null) {
+            delete node.attributes[attr];
+          }
+        }
+      },
+      exit: (node, parentNode) => {
+        if (node.name !== 'a') {
+          return;
+        }
+
+        for (const attr of Object.keys(node.attributes)) {
+          if (attr === 'href' || attr.endsWith(':href')) {
+            if (
+              node.attributes[attr] == null ||
+              !node.attributes[attr].trimStart().startsWith('javascript:')
+            ) {
+              continue;
+            }
+
+            const index = parentNode.children.indexOf(node);
+            parentNode.children.splice(index, 1, ...node.children);
+
+            // TODO remove legacy parentNode in v4
+            for (const child of node.children) {
+              Object.defineProperty(child, 'parentNode', {
+                writable: true,
+                value: parentNode,
+              });
+            }
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeStyleElement.js

@@ -0,0 +1,27 @@
+'use strict';
+
+const { detachNodeFromParent } = require('../lib/xast.js');
+
+exports.name = 'removeStyleElement';
+exports.description = 'removes <style> element (disabled by default)';
+
+/**
+ * Remove <style>.
+ *
+ * https://www.w3.org/TR/SVG11/styling.html#StyleElement
+ *
+ * @author Betsy Dupuis
+ *
+ * @type {import('./plugins-types').Plugin<'removeStyleElement'>}
+ */
+exports.fn = () => {
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        if (node.name === 'style') {
+          detachNodeFromParent(node, parentNode);
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeTitle.js

@@ -0,0 +1,27 @@
+'use strict';
+
+const { detachNodeFromParent } = require('../lib/xast.js');
+
+exports.name = 'removeTitle';
+exports.description = 'removes <title>';
+
+/**
+ * Remove <title>.
+ *
+ * https://developer.mozilla.org/docs/Web/SVG/Element/title
+ *
+ * @author Igor Kalashnikov
+ *
+ * @type {import('./plugins-types').Plugin<'removeTitle'>}
+ */
+exports.fn = () => {
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        if (node.name === 'title') {
+          detachNodeFromParent(node, parentNode);
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeUnknownsAndDefaults.js

@@ -0,0 +1,212 @@
+'use strict';
+
+const { visitSkip, detachNodeFromParent } = require('../lib/xast.js');
+const { collectStylesheet, computeStyle } = require('../lib/style.js');
+const {
+  elems,
+  attrsGroups,
+  elemsGroups,
+  attrsGroupsDefaults,
+  presentationNonInheritableGroupAttrs,
+} = require('./_collections');
+
+exports.name = 'removeUnknownsAndDefaults';
+exports.description =
+  'removes unknown elements content and attributes, removes attrs with default values';
+
+// resolve all groups references
+
+/**
+ * @type {Map<string, Set<string>>}
+ */
+const allowedChildrenPerElement = new Map();
+/**
+ * @type {Map<string, Set<string>>}
+ */
+const allowedAttributesPerElement = new Map();
+/**
+ * @type {Map<string, Map<string, string>>}
+ */
+const attributesDefaultsPerElement = new Map();
+
+for (const [name, config] of Object.entries(elems)) {
+  /**
+   * @type {Set<string>}
+   */
+  const allowedChildren = new Set();
+  if (config.content) {
+    for (const elementName of config.content) {
+      allowedChildren.add(elementName);
+    }
+  }
+  if (config.contentGroups) {
+    for (const contentGroupName of config.contentGroups) {
+      const elemsGroup = elemsGroups[contentGroupName];
+      if (elemsGroup) {
+        for (const elementName of elemsGroup) {
+          allowedChildren.add(elementName);
+        }
+      }
+    }
+  }
+  /**
+   * @type {Set<string>}
+   */
+  const allowedAttributes = new Set();
+  if (config.attrs) {
+    for (const attrName of config.attrs) {
+      allowedAttributes.add(attrName);
+    }
+  }
+  /**
+   * @type {Map<string, string>}
+   */
+  const attributesDefaults = new Map();
+  if (config.defaults) {
+    for (const [attrName, defaultValue] of Object.entries(config.defaults)) {
+      attributesDefaults.set(attrName, defaultValue);
+    }
+  }
+  for (const attrsGroupName of config.attrsGroups) {
+    const attrsGroup = attrsGroups[attrsGroupName];
+    if (attrsGroup) {
+      for (const attrName of attrsGroup) {
+        allowedAttributes.add(attrName);
+      }
+    }
+    const groupDefaults = attrsGroupsDefaults[attrsGroupName];
+    if (groupDefaults) {
+      for (const [attrName, defaultValue] of Object.entries(groupDefaults)) {
+        attributesDefaults.set(attrName, defaultValue);
+      }
+    }
+  }
+  allowedChildrenPerElement.set(name, allowedChildren);
+  allowedAttributesPerElement.set(name, allowedAttributes);
+  attributesDefaultsPerElement.set(name, attributesDefaults);
+}
+
+/**
+ * Remove unknown elements content and attributes,
+ * remove attributes with default values.
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'removeUnknownsAndDefaults'>}
+ */
+exports.fn = (root, params) => {
+  const {
+    unknownContent = true,
+    unknownAttrs = true,
+    defaultAttrs = true,
+    defaultMarkupDeclarations = true,
+    uselessOverrides = true,
+    keepDataAttrs = true,
+    keepAriaAttrs = true,
+    keepRoleAttr = false,
+  } = params;
+  const stylesheet = collectStylesheet(root);
+
+  return {
+    instruction: {
+      enter: (node) => {
+        if (defaultMarkupDeclarations) {
+          node.value = node.value.replace(/\s*standalone\s*=\s*(["'])no\1/, '');
+        }
+      },
+    },
+    element: {
+      enter: (node, parentNode) => {
+        // skip namespaced elements
+        if (node.name.includes(':')) {
+          return;
+        }
+        // skip visiting foreignObject subtree
+        if (node.name === 'foreignObject') {
+          return visitSkip;
+        }
+
+        // remove unknown element's content
+        if (unknownContent && parentNode.type === 'element') {
+          const allowedChildren = allowedChildrenPerElement.get(
+            parentNode.name,
+          );
+          if (allowedChildren == null || allowedChildren.size === 0) {
+            // remove unknown elements
+            if (allowedChildrenPerElement.get(node.name) == null) {
+              detachNodeFromParent(node, parentNode);
+              return;
+            }
+          } else {
+            // remove not allowed children
+            if (allowedChildren.has(node.name) === false) {
+              detachNodeFromParent(node, parentNode);
+              return;
+            }
+          }
+        }
+
+        const allowedAttributes = allowedAttributesPerElement.get(node.name);
+        const attributesDefaults = attributesDefaultsPerElement.get(node.name);
+        const computedParentStyle =
+          parentNode.type === 'element'
+            ? computeStyle(stylesheet, parentNode)
+            : null;
+
+        // remove element's unknown attrs and attrs with default values
+        for (const [name, value] of Object.entries(node.attributes)) {
+          if (keepDataAttrs && name.startsWith('data-')) {
+            continue;
+          }
+          if (keepAriaAttrs && name.startsWith('aria-')) {
+            continue;
+          }
+          if (keepRoleAttr && name === 'role') {
+            continue;
+          }
+          // skip xmlns attribute
+          if (name === 'xmlns') {
+            continue;
+          }
+          // skip namespaced attributes except xml:* and xlink:*
+          if (name.includes(':')) {
+            const [prefix] = name.split(':');
+            if (prefix !== 'xml' && prefix !== 'xlink') {
+              continue;
+            }
+          }
+
+          if (
+            unknownAttrs &&
+            allowedAttributes &&
+            allowedAttributes.has(name) === false
+          ) {
+            delete node.attributes[name];
+          }
+          if (
+            defaultAttrs &&
+            node.attributes.id == null &&
+            attributesDefaults &&
+            attributesDefaults.get(name) === value
+          ) {
+            // keep defaults if parent has own or inherited style
+            if (computedParentStyle?.[name] == null) {
+              delete node.attributes[name];
+            }
+          }
+          if (uselessOverrides && node.attributes.id == null) {
+            const style = computedParentStyle?.[name];
+            if (
+              presentationNonInheritableGroupAttrs.has(name) === false &&
+              style != null &&
+              style.type === 'static' &&
+              style.value === value
+            ) {
+              delete node.attributes[name];
+            }
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeUnusedNS.js

@@ -0,0 +1,59 @@
+'use strict';
+
+exports.name = 'removeUnusedNS';
+exports.description = 'removes unused namespaces declaration';
+
+/**
+ * Remove unused namespaces declaration from svg element
+ * which are not used in elements or attributes
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'removeUnusedNS'>}
+ */
+exports.fn = () => {
+  /**
+   * @type {Set<string>}
+   */
+  const unusedNamespaces = new Set();
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        // collect all namespaces from svg element
+        // (such as xmlns:xlink="http://www.w3.org/1999/xlink")
+        if (node.name === 'svg' && parentNode.type === 'root') {
+          for (const name of Object.keys(node.attributes)) {
+            if (name.startsWith('xmlns:')) {
+              const local = name.slice('xmlns:'.length);
+              unusedNamespaces.add(local);
+            }
+          }
+        }
+        if (unusedNamespaces.size !== 0) {
+          // preserve namespace used in nested elements names
+          if (node.name.includes(':')) {
+            const [ns] = node.name.split(':');
+            if (unusedNamespaces.has(ns)) {
+              unusedNamespaces.delete(ns);
+            }
+          }
+          // preserve namespace used in nested elements attributes
+          for (const name of Object.keys(node.attributes)) {
+            if (name.includes(':')) {
+              const [ns] = name.split(':');
+              unusedNamespaces.delete(ns);
+            }
+          }
+        }
+      },
+      exit: (node, parentNode) => {
+        // remove unused namespace attributes from svg element
+        if (node.name === 'svg' && parentNode.type === 'root') {
+          for (const name of unusedNamespaces) {
+            delete node.attributes[`xmlns:${name}`];
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeUselessDefs.js

@@ -0,0 +1,65 @@
+'use strict';
+
+/**
+ * @typedef {import('../lib/types').XastElement} XastElement
+ */
+
+const { detachNodeFromParent } = require('../lib/xast.js');
+const { elemsGroups } = require('./_collections.js');
+
+exports.name = 'removeUselessDefs';
+exports.description = 'removes elements in <defs> without id';
+
+/**
+ * Removes content of defs and properties that aren't rendered directly without ids.
+ *
+ * @author Lev Solntsev
+ *
+ * @type {import('./plugins-types').Plugin<'removeUselessDefs'>}
+ */
+exports.fn = () => {
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        if (node.name === 'defs') {
+          /**
+           * @type {XastElement[]}
+           */
+          const usefulNodes = [];
+          collectUsefulNodes(node, usefulNodes);
+          if (usefulNodes.length === 0) {
+            detachNodeFromParent(node, parentNode);
+          }
+          // TODO remove legacy parentNode in v4
+          for (const usefulNode of usefulNodes) {
+            Object.defineProperty(usefulNode, 'parentNode', {
+              writable: true,
+              value: node,
+            });
+          }
+          node.children = usefulNodes;
+        } else if (
+          elemsGroups.nonRendering.has(node.name) &&
+          node.attributes.id == null
+        ) {
+          detachNodeFromParent(node, parentNode);
+        }
+      },
+    },
+  };
+};
+
+/**
+ * @type {(node: XastElement, usefulNodes: XastElement[]) => void}
+ */
+const collectUsefulNodes = (node, usefulNodes) => {
+  for (const child of node.children) {
+    if (child.type === 'element') {
+      if (child.attributes.id != null || child.name === 'style') {
+        usefulNodes.push(child);
+      } else {
+        collectUsefulNodes(child, usefulNodes);
+      }
+    }
+  }
+};

backend/node_modules/svgo/plugins/removeUselessStrokeAndFill.js

@@ -0,0 +1,139 @@
+'use strict';
+
+const { visit, visitSkip, detachNodeFromParent } = require('../lib/xast.js');
+const { collectStylesheet, computeStyle } = require('../lib/style.js');
+const { hasScripts } = require('../lib/svgo/tools.js');
+const { elemsGroups } = require('./_collections.js');
+
+exports.name = 'removeUselessStrokeAndFill';
+exports.description = 'removes useless stroke and fill attributes';
+
+/**
+ * Remove useless stroke and fill attrs.
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'removeUselessStrokeAndFill'>}
+ */
+exports.fn = (root, params) => {
+  const {
+    stroke: removeStroke = true,
+    fill: removeFill = true,
+    removeNone = false,
+  } = params;
+
+  // style and script elements deoptimise this plugin
+  let hasStyleOrScript = false;
+  visit(root, {
+    element: {
+      enter: (node) => {
+        if (node.name === 'style' || hasScripts(node)) {
+          hasStyleOrScript = true;
+        }
+      },
+    },
+  });
+  if (hasStyleOrScript) {
+    return null;
+  }
+
+  const stylesheet = collectStylesheet(root);
+
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        // id attribute deoptimise the whole subtree
+        if (node.attributes.id != null) {
+          return visitSkip;
+        }
+        if (!elemsGroups.shape.has(node.name)) {
+          return;
+        }
+        const computedStyle = computeStyle(stylesheet, node);
+        const stroke = computedStyle.stroke;
+        const strokeOpacity = computedStyle['stroke-opacity'];
+        const strokeWidth = computedStyle['stroke-width'];
+        const markerEnd = computedStyle['marker-end'];
+        const fill = computedStyle.fill;
+        const fillOpacity = computedStyle['fill-opacity'];
+        const computedParentStyle =
+          parentNode.type === 'element'
+            ? computeStyle(stylesheet, parentNode)
+            : null;
+        const parentStroke =
+          computedParentStyle == null ? null : computedParentStyle.stroke;
+
+        // remove stroke*
+        if (removeStroke) {
+          if (
+            stroke == null ||
+            (stroke.type === 'static' && stroke.value == 'none') ||
+            (strokeOpacity != null &&
+              strokeOpacity.type === 'static' &&
+              strokeOpacity.value === '0') ||
+            (strokeWidth != null &&
+              strokeWidth.type === 'static' &&
+              strokeWidth.value === '0')
+          ) {
+            // stroke-width may affect the size of marker-end
+            // marker is not visible when stroke-width is 0
+            if (
+              (strokeWidth != null &&
+                strokeWidth.type === 'static' &&
+                strokeWidth.value === '0') ||
+              markerEnd == null
+            ) {
+              for (const name of Object.keys(node.attributes)) {
+                if (name.startsWith('stroke')) {
+                  delete node.attributes[name];
+                }
+              }
+              // set explicit none to not inherit from parent
+              if (
+                parentStroke != null &&
+                parentStroke.type === 'static' &&
+                parentStroke.value !== 'none'
+              ) {
+                node.attributes.stroke = 'none';
+              }
+            }
+          }
+        }
+
+        // remove fill*
+        if (removeFill) {
+          if (
+            (fill != null && fill.type === 'static' && fill.value === 'none') ||
+            (fillOpacity != null &&
+              fillOpacity.type === 'static' &&
+              fillOpacity.value === '0')
+          ) {
+            for (const name of Object.keys(node.attributes)) {
+              if (name.startsWith('fill-')) {
+                delete node.attributes[name];
+              }
+            }
+            if (
+              fill == null ||
+              (fill.type === 'static' && fill.value !== 'none')
+            ) {
+              node.attributes.fill = 'none';
+            }
+          }
+        }
+
+        if (removeNone) {
+          if (
+            (stroke == null || node.attributes.stroke === 'none') &&
+            ((fill != null &&
+              fill.type === 'static' &&
+              fill.value === 'none') ||
+              node.attributes.fill === 'none')
+          ) {
+            detachNodeFromParent(node, parentNode);
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeViewBox.js

@@ -0,0 +1,49 @@
+'use strict';
+
+exports.name = 'removeViewBox';
+exports.description = 'removes viewBox attribute when possible';
+
+const viewBoxElems = new Set(['pattern', 'svg', 'symbol']);
+
+/**
+ * Remove viewBox attr which coincides with a width/height box.
+ *
+ * @see https://www.w3.org/TR/SVG11/coords.html#ViewBoxAttribute
+ *
+ * @example
+ * <svg width="100" height="50" viewBox="0 0 100 50">
+ *             ⬇
+ * <svg width="100" height="50">
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'removeViewBox'>}
+ */
+exports.fn = () => {
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        if (
+          viewBoxElems.has(node.name) &&
+          node.attributes.viewBox != null &&
+          node.attributes.width != null &&
+          node.attributes.height != null
+        ) {
+          // TODO remove width/height for such case instead
+          if (node.name === 'svg' && parentNode.type !== 'root') {
+            return;
+          }
+          const nums = node.attributes.viewBox.split(/[ ,]+/g);
+          if (
+            nums[0] === '0' &&
+            nums[1] === '0' &&
+            node.attributes.width.replace(/px$/, '') === nums[2] && // could use parseFloat too
+            node.attributes.height.replace(/px$/, '') === nums[3]
+          ) {
+            delete node.attributes.viewBox;
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeXMLNS.js

@@ -0,0 +1,29 @@
+'use strict';
+
+exports.name = 'removeXMLNS';
+exports.description =
+  'removes xmlns attribute (for inline svg, disabled by default)';
+
+/**
+ * Remove the xmlns attribute when present.
+ *
+ * @example
+ * <svg viewBox="0 0 100 50" xmlns="http://www.w3.org/2000/svg">
+ *   ↓
+ * <svg viewBox="0 0 100 50">
+ *
+ * @author Ricardo Tomasi
+ *
+ * @type {import('./plugins-types').Plugin<'removeXMLNS'>}
+ */
+exports.fn = () => {
+  return {
+    element: {
+      enter: (node) => {
+        if (node.name === 'svg') {
+          delete node.attributes.xmlns;
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeXMLProcInst.js

@@ -0,0 +1,28 @@
+'use strict';
+
+const { detachNodeFromParent } = require('../lib/xast.js');
+
+exports.name = 'removeXMLProcInst';
+exports.description = 'removes XML processing instructions';
+
+/**
+ * Remove XML Processing Instruction.
+ *
+ * @example
+ * <?xml version="1.0" encoding="utf-8"?>
+ *
+ * @author Kir Belevich
+ *
+ * @type {import('./plugins-types').Plugin<'removeXMLProcInst'>}
+ */
+exports.fn = () => {
+  return {
+    instruction: {
+      enter: (node, parentNode) => {
+        if (node.name === 'xml') {
+          detachNodeFromParent(node, parentNode);
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/removeXlink.js

@@ -0,0 +1,226 @@
+'use strict';
+
+const { elems } = require('./_collections');
+
+/**
+ * @typedef {import('../lib/types').XastElement} XastElement
+ */
+
+exports.name = 'removeXlink';
+exports.description =
+  'remove xlink namespace and replaces attributes with the SVG 2 equivalent where applicable';
+
+/** URI indicating the Xlink namespace. */
+const XLINK_NAMESPACE = 'http://www.w3.org/1999/xlink';
+
+/**
+ * Map of `xlink:show` values to the SVG 2 `target` attribute values.
+ *
+ * @type {Record<string, string>}
+ * @see https://developer.mozilla.org/docs/Web/SVG/Attribute/xlink:show#usage_notes
+ */
+const SHOW_TO_TARGET = {
+  new: '_blank',
+  replace: '_self',
+};
+
+/**
+ * Elements that use xlink:href, but were deprecated in SVG 2 and therefore
+ * don't support the SVG 2 href attribute.
+ *
+ * @type {Set<string>}
+ * @see https://developer.mozilla.org/docs/Web/SVG/Attribute/xlink:href
+ * @see https://developer.mozilla.org/docs/Web/SVG/Attribute/href
+ */
+const LEGACY_ELEMENTS = new Set([
+  'cursor',
+  'filter',
+  'font-face-uri',
+  'glyphRef',
+  'tref',
+]);
+
+/**
+ * @param {XastElement} node
+ * @param {string[]} prefixes
+ * @param {string} attr
+ * @returns {string[]}
+ */
+const findPrefixedAttrs = (node, prefixes, attr) => {
+  return prefixes
+    .map((prefix) => `${prefix}:${attr}`)
+    .filter((attr) => node.attributes[attr] != null);
+};
+
+/**
+ * Removes XLink namespace prefixes and converts references to XLink attributes
+ * to the native SVG equivalent.
+ *
+ * The XLink namespace is deprecated in SVG 2.
+ *
+ * @type {import('./plugins-types').Plugin<'removeXlink'>}
+ * @see https://developer.mozilla.org/docs/Web/SVG/Attribute/xlink:href
+ */
+exports.fn = (_, params) => {
+  const { includeLegacy } = params;
+
+  /**
+   * XLink namespace prefixes that are currently in the stack.
+   *
+   * @type {string[]}
+   */
+  const xlinkPrefixes = [];
+
+  /**
+   * Namespace prefixes that exist in {@link xlinkPrefixes} but were overridden
+   * in a child element to point to another namespace, and so is not treated as
+   * an XLink attribute.
+   *
+   * @type {string[]}
+   */
+  const overriddenPrefixes = [];
+
+  /**
+   * Namespace prefixes that were used in one of the {@link LEGACY_ELEMENTS}.
+   *
+   * @type {string[]}
+   */
+  const usedInLegacyElement = [];
+
+  return {
+    element: {
+      enter: (node) => {
+        for (const [key, value] of Object.entries(node.attributes)) {
+          if (key.startsWith('xmlns:')) {
+            const prefix = key.split(':', 2)[1];
+
+            if (value === XLINK_NAMESPACE) {
+              xlinkPrefixes.push(prefix);
+              continue;
+            }
+
+            if (xlinkPrefixes.includes(prefix)) {
+              overriddenPrefixes.push(prefix);
+            }
+          }
+        }
+
+        if (
+          overriddenPrefixes.some((prefix) => xlinkPrefixes.includes(prefix))
+        ) {
+          return;
+        }
+
+        const showAttrs = findPrefixedAttrs(node, xlinkPrefixes, 'show');
+        let showHandled = node.attributes.target != null;
+        for (let i = showAttrs.length - 1; i >= 0; i--) {
+          const attr = showAttrs[i];
+          const value = node.attributes[attr];
+          const mapping = SHOW_TO_TARGET[value];
+
+          if (showHandled || mapping == null) {
+            delete node.attributes[attr];
+            continue;
+          }
+
+          if (mapping !== elems[node.name]?.defaults?.target) {
+            node.attributes.target = mapping;
+          }
+
+          delete node.attributes[attr];
+          showHandled = true;
+        }
+
+        const titleAttrs = findPrefixedAttrs(node, xlinkPrefixes, 'title');
+        for (let i = titleAttrs.length - 1; i >= 0; i--) {
+          const attr = titleAttrs[i];
+          const value = node.attributes[attr];
+          const hasTitle = node.children.filter(
+            (child) => child.type === 'element' && child.name === 'title',
+          );
+
+          if (hasTitle.length > 0) {
+            delete node.attributes[attr];
+            continue;
+          }
+
+          /** @type {XastElement} */
+          const titleTag = {
+            type: 'element',
+            name: 'title',
+            attributes: {},
+            children: [
+              {
+                type: 'text',
+                value,
+              },
+            ],
+          };
+
+          Object.defineProperty(titleTag, 'parentNode', {
+            writable: true,
+            value: node,
+          });
+
+          node.children.unshift(titleTag);
+          delete node.attributes[attr];
+        }
+
+        const hrefAttrs = findPrefixedAttrs(node, xlinkPrefixes, 'href');
+
+        if (
+          hrefAttrs.length > 0 &&
+          LEGACY_ELEMENTS.has(node.name) &&
+          !includeLegacy
+        ) {
+          hrefAttrs
+            .map((attr) => attr.split(':', 1)[0])
+            .forEach((prefix) => usedInLegacyElement.push(prefix));
+          return;
+        }
+
+        for (let i = hrefAttrs.length - 1; i >= 0; i--) {
+          const attr = hrefAttrs[i];
+          const value = node.attributes[attr];
+
+          if (node.attributes.href != null) {
+            delete node.attributes[attr];
+            continue;
+          }
+
+          node.attributes.href = value;
+          delete node.attributes[attr];
+        }
+      },
+      exit: (node) => {
+        for (const [key, value] of Object.entries(node.attributes)) {
+          const [prefix, attr] = key.split(':', 2);
+
+          if (
+            xlinkPrefixes.includes(prefix) &&
+            !overriddenPrefixes.includes(prefix) &&
+            !usedInLegacyElement.includes(prefix) &&
+            !includeLegacy
+          ) {
+            delete node.attributes[key];
+            continue;
+          }
+
+          if (key.startsWith('xmlns:') && !usedInLegacyElement.includes(attr)) {
+            if (value === XLINK_NAMESPACE) {
+              const index = xlinkPrefixes.indexOf(attr);
+              xlinkPrefixes.splice(index, 1);
+              delete node.attributes[key];
+              continue;
+            }
+
+            if (overriddenPrefixes.includes(prefix)) {
+              const index = overriddenPrefixes.indexOf(attr);
+              overriddenPrefixes.splice(index, 1);
+            }
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/reusePaths.js

@@ -0,0 +1,195 @@
+'use strict';
+
+const { collectStylesheet } = require('../lib/style');
+const { detachNodeFromParent, querySelectorAll } = require('../lib/xast');
+
+/**
+ * @typedef {import('../lib/types').XastElement} XastElement
+ * @typedef {import('../lib/types').XastParent} XastParent
+ * @typedef {import('../lib/types').XastNode} XastNode
+ */
+
+exports.name = 'reusePaths';
+exports.description =
+  'Finds <path> elements with the same d, fill, and ' +
+  'stroke, and converts them to <use> elements ' +
+  'referencing a single <path> def.';
+
+/**
+ * Finds <path> elements with the same d, fill, and stroke, and converts them to
+ * <use> elements referencing a single <path> def.
+ *
+ * @author Jacob Howcroft
+ *
+ * @type {import('./plugins-types').Plugin<'reusePaths'>}
+ */
+exports.fn = (root) => {
+  const stylesheet = collectStylesheet(root);
+
+  /**
+   * @type {Map<string, XastElement[]>}
+   */
+  const paths = new Map();
+
+  /**
+   * Reference to the first defs element that is a direct child of the svg
+   * element if one exists.
+   *
+   * @type {XastElement}
+   * @see https://developer.mozilla.org/docs/Web/SVG/Element/defs
+   */
+  let svgDefs;
+
+  /**
+   * Set of hrefs that reference the id of another node.
+   *
+   * @type {Set<string>}
+   */
+  const hrefs = new Set();
+
+  return {
+    element: {
+      enter: (node, parentNode) => {
+        if (node.name === 'path' && node.attributes.d != null) {
+          const d = node.attributes.d;
+          const fill = node.attributes.fill || '';
+          const stroke = node.attributes.stroke || '';
+          const key = d + ';s:' + stroke + ';f:' + fill;
+          let list = paths.get(key);
+          if (list == null) {
+            list = [];
+            paths.set(key, list);
+          }
+          list.push(node);
+        }
+
+        if (
+          svgDefs == null &&
+          node.name === 'defs' &&
+          parentNode.type === 'element' &&
+          parentNode.name === 'svg'
+        ) {
+          svgDefs = node;
+        }
+
+        if (node.name === 'use') {
+          for (const name of ['href', 'xlink:href']) {
+            const href = node.attributes[name];
+
+            if (href != null && href.startsWith('#') && href.length > 1) {
+              hrefs.add(href.slice(1));
+            }
+          }
+        }
+      },
+
+      exit: (node, parentNode) => {
+        if (node.name === 'svg' && parentNode.type === 'root') {
+          let defsTag = svgDefs;
+
+          if (defsTag == null) {
+            defsTag = {
+              type: 'element',
+              name: 'defs',
+              attributes: {},
+              children: [],
+            };
+            // TODO remove legacy parentNode in v4
+            Object.defineProperty(defsTag, 'parentNode', {
+              writable: true,
+              value: node,
+            });
+          }
+
+          let index = 0;
+          for (const list of paths.values()) {
+            if (list.length > 1) {
+              /** @type {XastElement} */
+              const reusablePath = {
+                type: 'element',
+                name: 'path',
+                attributes: {},
+                children: [],
+              };
+
+              for (const attr of ['fill', 'stroke', 'd']) {
+                if (list[0].attributes[attr] != null) {
+                  reusablePath.attributes[attr] = list[0].attributes[attr];
+                }
+              }
+
+              const originalId = list[0].attributes.id;
+              if (
+                originalId == null ||
+                hrefs.has(originalId) ||
+                stylesheet.rules.some(
+                  (rule) => rule.selector === `#${originalId}`,
+                )
+              ) {
+                reusablePath.attributes.id = 'reuse-' + index++;
+              } else {
+                reusablePath.attributes.id = originalId;
+                delete list[0].attributes.id;
+              }
+              // TODO remove legacy parentNode in v4
+              Object.defineProperty(reusablePath, 'parentNode', {
+                writable: true,
+                value: defsTag,
+              });
+              defsTag.children.push(reusablePath);
+              // convert paths to <use>
+              for (const pathNode of list) {
+                delete pathNode.attributes.d;
+                delete pathNode.attributes.stroke;
+                delete pathNode.attributes.fill;
+
+                if (
+                  defsTag.children.includes(pathNode) &&
+                  pathNode.children.length === 0
+                ) {
+                  if (Object.keys(pathNode.attributes).length === 0) {
+                    detachNodeFromParent(pathNode, defsTag);
+                    continue;
+                  }
+
+                  if (
+                    Object.keys(pathNode.attributes).length === 1 &&
+                    pathNode.attributes.id != null
+                  ) {
+                    detachNodeFromParent(pathNode, defsTag);
+                    const selector = `[xlink\\:href=#${pathNode.attributes.id}], [href=#${pathNode.attributes.id}]`;
+                    for (const child of querySelectorAll(node, selector)) {
+                      if (child.type !== 'element') {
+                        continue;
+                      }
+                      for (const name of ['href', 'xlink:href']) {
+                        if (child.attributes[name] != null) {
+                          child.attributes[name] =
+                            '#' + reusablePath.attributes.id;
+                        }
+                      }
+                    }
+                    continue;
+                  }
+                }
+
+                pathNode.name = 'use';
+                pathNode.attributes['xlink:href'] =
+                  '#' + reusablePath.attributes.id;
+              }
+            }
+          }
+          if (defsTag.children.length !== 0) {
+            if (node.attributes['xmlns:xlink'] == null) {
+              node.attributes['xmlns:xlink'] = 'http://www.w3.org/1999/xlink';
+            }
+
+            if (svgDefs == null) {
+              node.children.unshift(defsTag);
+            }
+          }
+        }
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/sortAttrs.js

@@ -0,0 +1,108 @@
+'use strict';
+
+exports.name = 'sortAttrs';
+exports.description = 'Sort element attributes for better compression';
+
+/**
+ * Sort element attributes for better compression
+ *
+ * @author Nikolay Frantsev
+ *
+ * @type {import('./plugins-types').Plugin<'sortAttrs'>}
+ */
+exports.fn = (_root, params) => {
+  const {
+    order = [
+      'id',
+      'width',
+      'height',
+      'x',
+      'x1',
+      'x2',
+      'y',
+      'y1',
+      'y2',
+      'cx',
+      'cy',
+      'r',
+      'fill',
+      'stroke',
+      'marker',
+      'd',
+      'points',
+    ],
+    xmlnsOrder = 'front',
+  } = params;
+
+  /**
+   * @type {(name: string) => number}
+   */
+  const getNsPriority = (name) => {
+    if (xmlnsOrder === 'front') {
+      // put xmlns first
+      if (name === 'xmlns') {
+        return 3;
+      }
+      // xmlns:* attributes second
+      if (name.startsWith('xmlns:')) {
+        return 2;
+      }
+    }
+    // other namespaces after and sort them alphabetically
+    if (name.includes(':')) {
+      return 1;
+    }
+    // other attributes
+    return 0;
+  };
+
+  /**
+   * @type {(a: [string, string], b: [string, string]) => number}
+   */
+  const compareAttrs = ([aName], [bName]) => {
+    // sort namespaces
+    const aPriority = getNsPriority(aName);
+    const bPriority = getNsPriority(bName);
+    const priorityNs = bPriority - aPriority;
+    if (priorityNs !== 0) {
+      return priorityNs;
+    }
+    // extract the first part from attributes
+    // for example "fill" from "fill" and "fill-opacity"
+    const [aPart] = aName.split('-');
+    const [bPart] = bName.split('-');
+    // rely on alphabetical sort when the first part is the same
+    if (aPart !== bPart) {
+      const aInOrderFlag = order.includes(aPart) ? 1 : 0;
+      const bInOrderFlag = order.includes(bPart) ? 1 : 0;
+      // sort by position in order param
+      if (aInOrderFlag === 1 && bInOrderFlag === 1) {
+        return order.indexOf(aPart) - order.indexOf(bPart);
+      }
+      // put attributes from order param before others
+      const priorityOrder = bInOrderFlag - aInOrderFlag;
+      if (priorityOrder !== 0) {
+        return priorityOrder;
+      }
+    }
+    // sort alphabetically
+    return aName < bName ? -1 : 1;
+  };
+
+  return {
+    element: {
+      enter: (node) => {
+        const attrs = Object.entries(node.attributes);
+        attrs.sort(compareAttrs);
+        /**
+         * @type {Record<string, string>}
+         */
+        const sortedAttributes = {};
+        for (const [name, value] of attrs) {
+          sortedAttributes[name] = value;
+        }
+        node.attributes = sortedAttributes;
+      },
+    },
+  };
+};

backend/node_modules/svgo/plugins/sortDefsChildren.js

@@ -0,0 +1,58 @@
+'use strict';
+
+exports.name = 'sortDefsChildren';
+exports.description = 'Sorts children of <defs> to improve compression';
+
+/**
+ * Sorts children of defs in order to improve compression.
+ * Sorted first by frequency then by element name length then by element name (to ensure grouping).
+ *
+ * @author David Leston
+ *
+ * @type {import('./plugins-types').Plugin<'sortDefsChildren'>}
+ */
+exports.fn = () => {
+  return {
+    element: {
+      enter: (node) => {
+        if (node.name === 'defs') {
+          /**
+           * @type {Map<string, number>}
+           */
+          const frequencies = new Map();
+          for (const child of node.children) {
+            if (child.type === 'element') {
+              const frequency = frequencies.get(child.name);
+              if (frequency == null) {
+                frequencies.set(child.name, 1);
+              } else {
+                frequencies.set(child.name, frequency + 1);
+              }
+            }
+          }
+          node.children.sort((a, b) => {
+            if (a.type !== 'element' || b.type !== 'element') {
+              return 0;
+            }
+            const aFrequency = frequencies.get(a.name);
+            const bFrequency = frequencies.get(b.name);
+            if (aFrequency != null && bFrequency != null) {
+              const frequencyComparison = bFrequency - aFrequency;
+              if (frequencyComparison !== 0) {
+                return frequencyComparison;
+              }
+            }
+            const lengthComparison = b.name.length - a.name.length;
+            if (lengthComparison !== 0) {
+              return lengthComparison;
+            }
+            if (a.name !== b.name) {
+              return a.name > b.name ? -1 : 1;
+            }
+            return 0;
+          });
+        }
+      },
+    },
+  };
+};