It appears you have a well-structured Git repository with various files, including SVG icons and HTML documents. Here's a brief overview:

backend/node_modules/svgo/lib/builtin.js

@@ -0,0 +1,57 @@
+'use strict';
+
+exports.builtin = [
+  require('../plugins/preset-default.js'),
+  require('../plugins/addAttributesToSVGElement.js'),
+  require('../plugins/addClassesToSVGElement.js'),
+  require('../plugins/cleanupAttrs.js'),
+  require('../plugins/cleanupEnableBackground.js'),
+  require('../plugins/cleanupIds.js'),
+  require('../plugins/cleanupListOfValues.js'),
+  require('../plugins/cleanupNumericValues.js'),
+  require('../plugins/collapseGroups.js'),
+  require('../plugins/convertColors.js'),
+  require('../plugins/convertEllipseToCircle.js'),
+  require('../plugins/convertOneStopGradients.js'),
+  require('../plugins/convertPathData.js'),
+  require('../plugins/convertShapeToPath.js'),
+  require('../plugins/convertStyleToAttrs.js'),
+  require('../plugins/convertTransform.js'),
+  require('../plugins/mergeStyles.js'),
+  require('../plugins/inlineStyles.js'),
+  require('../plugins/mergePaths.js'),
+  require('../plugins/minifyStyles.js'),
+  require('../plugins/moveElemsAttrsToGroup.js'),
+  require('../plugins/moveGroupAttrsToElems.js'),
+  require('../plugins/prefixIds.js'),
+  require('../plugins/removeAttributesBySelector.js'),
+  require('../plugins/removeAttrs.js'),
+  require('../plugins/removeComments.js'),
+  require('../plugins/removeDesc.js'),
+  require('../plugins/removeDimensions.js'),
+  require('../plugins/removeDoctype.js'),
+  require('../plugins/removeEditorsNSData.js'),
+  require('../plugins/removeElementsByAttr.js'),
+  require('../plugins/removeEmptyAttrs.js'),
+  require('../plugins/removeEmptyContainers.js'),
+  require('../plugins/removeEmptyText.js'),
+  require('../plugins/removeHiddenElems.js'),
+  require('../plugins/removeMetadata.js'),
+  require('../plugins/removeNonInheritableGroupAttrs.js'),
+  require('../plugins/removeOffCanvasPaths.js'),
+  require('../plugins/removeRasterImages.js'),
+  require('../plugins/removeScriptElement.js'),
+  require('../plugins/removeStyleElement.js'),
+  require('../plugins/removeTitle.js'),
+  require('../plugins/removeUnknownsAndDefaults.js'),
+  require('../plugins/removeUnusedNS.js'),
+  require('../plugins/removeUselessDefs.js'),
+  require('../plugins/removeUselessStrokeAndFill.js'),
+  require('../plugins/removeViewBox.js'),
+  require('../plugins/removeXlink.js'),
+  require('../plugins/removeXMLNS.js'),
+  require('../plugins/removeXMLProcInst.js'),
+  require('../plugins/reusePaths.js'),
+  require('../plugins/sortAttrs.js'),
+  require('../plugins/sortDefsChildren.js'),
+];

backend/node_modules/svgo/lib/parser.js

@@ -0,0 +1,262 @@
+'use strict';
+
+/**
+ * @typedef {import('./types').XastNode} XastNode
+ * @typedef {import('./types').XastInstruction} XastInstruction
+ * @typedef {import('./types').XastDoctype} XastDoctype
+ * @typedef {import('./types').XastComment} XastComment
+ * @typedef {import('./types').XastRoot} XastRoot
+ * @typedef {import('./types').XastElement} XastElement
+ * @typedef {import('./types').XastCdata} XastCdata
+ * @typedef {import('./types').XastText} XastText
+ * @typedef {import('./types').XastParent} XastParent
+ * @typedef {import('./types').XastChild} XastChild
+ */
+
+// @ts-ignore sax will be replaced with something else later
+const SAX = require('@trysound/sax');
+const { textElems } = require('../plugins/_collections');
+
+class SvgoParserError extends Error {
+  /**
+   * @param message {string}
+   * @param line {number}
+   * @param column {number}
+   * @param source {string}
+   * @param file {void | string}
+   */
+  constructor(message, line, column, source, file) {
+    super(message);
+    this.name = 'SvgoParserError';
+    this.message = `${file || '<input>'}:${line}:${column}: ${message}`;
+    this.reason = message;
+    this.line = line;
+    this.column = column;
+    this.source = source;
+    if (Error.captureStackTrace) {
+      Error.captureStackTrace(this, SvgoParserError);
+    }
+  }
+  toString() {
+    const lines = this.source.split(/\r?\n/);
+    const startLine = Math.max(this.line - 3, 0);
+    const endLine = Math.min(this.line + 2, lines.length);
+    const lineNumberWidth = String(endLine).length;
+    const startColumn = Math.max(this.column - 54, 0);
+    const endColumn = Math.max(this.column + 20, 80);
+    const code = lines
+      .slice(startLine, endLine)
+      .map((line, index) => {
+        const lineSlice = line.slice(startColumn, endColumn);
+        let ellipsisPrefix = '';
+        let ellipsisSuffix = '';
+        if (startColumn !== 0) {
+          ellipsisPrefix = startColumn > line.length - 1 ? ' ' : '…';
+        }
+        if (endColumn < line.length - 1) {
+          ellipsisSuffix = '…';
+        }
+        const number = startLine + 1 + index;
+        const gutter = ` ${number.toString().padStart(lineNumberWidth)} | `;
+        if (number === this.line) {
+          const gutterSpacing = gutter.replace(/[^|]/g, ' ');
+          const lineSpacing = (
+            ellipsisPrefix + line.slice(startColumn, this.column - 1)
+          ).replace(/[^\t]/g, ' ');
+          const spacing = gutterSpacing + lineSpacing;
+          return `>${gutter}${ellipsisPrefix}${lineSlice}${ellipsisSuffix}\n ${spacing}^`;
+        }
+        return ` ${gutter}${ellipsisPrefix}${lineSlice}${ellipsisSuffix}`;
+      })
+      .join('\n');
+    return `${this.name}: ${this.message}\n\n${code}\n`;
+  }
+}
+
+const entityDeclaration = /<!ENTITY\s+(\S+)\s+(?:'([^']+)'|"([^"]+)")\s*>/g;
+
+const config = {
+  strict: true,
+  trim: false,
+  normalize: false,
+  lowercase: true,
+  xmlns: true,
+  position: true,
+};
+
+/**
+ * Convert SVG (XML) string to SVG-as-JS object.
+ *
+ * @type {(data: string, from?: string) => XastRoot}
+ */
+const parseSvg = (data, from) => {
+  const sax = SAX.parser(config.strict, config);
+  /**
+   * @type {XastRoot}
+   */
+  const root = { type: 'root', children: [] };
+  /**
+   * @type {XastParent}
+   */
+  let current = root;
+  /**
+   * @type {XastParent[]}
+   */
+  const stack = [root];
+
+  /**
+   * @type {(node: XastChild) => void}
+   */
+  const pushToContent = (node) => {
+    // TODO remove legacy parentNode in v4
+    Object.defineProperty(node, 'parentNode', {
+      writable: true,
+      value: current,
+    });
+    current.children.push(node);
+  };
+
+  /**
+   * @type {(doctype: string) => void}
+   */
+  sax.ondoctype = (doctype) => {
+    /**
+     * @type {XastDoctype}
+     */
+    const node = {
+      type: 'doctype',
+      // TODO parse doctype for name, public and system to match xast
+      name: 'svg',
+      data: {
+        doctype,
+      },
+    };
+    pushToContent(node);
+    const subsetStart = doctype.indexOf('[');
+    if (subsetStart >= 0) {
+      entityDeclaration.lastIndex = subsetStart;
+      let entityMatch = entityDeclaration.exec(data);
+      while (entityMatch != null) {
+        sax.ENTITIES[entityMatch[1]] = entityMatch[2] || entityMatch[3];
+        entityMatch = entityDeclaration.exec(data);
+      }
+    }
+  };
+
+  /**
+   * @type {(data: { name: string, body: string }) => void}
+   */
+  sax.onprocessinginstruction = (data) => {
+    /**
+     * @type {XastInstruction}
+     */
+    const node = {
+      type: 'instruction',
+      name: data.name,
+      value: data.body,
+    };
+    pushToContent(node);
+  };
+
+  /**
+   * @type {(comment: string) => void}
+   */
+  sax.oncomment = (comment) => {
+    /**
+     * @type {XastComment}
+     */
+    const node = {
+      type: 'comment',
+      value: comment.trim(),
+    };
+    pushToContent(node);
+  };
+
+  /**
+   * @type {(cdata: string) => void}
+   */
+  sax.oncdata = (cdata) => {
+    /**
+     * @type {XastCdata}
+     */
+    const node = {
+      type: 'cdata',
+      value: cdata,
+    };
+    pushToContent(node);
+  };
+
+  /**
+   * @type {(data: { name: string, attributes: Record<string, { value: string }>}) => void}
+   */
+  sax.onopentag = (data) => {
+    /**
+     * @type {XastElement}
+     */
+    let element = {
+      type: 'element',
+      name: data.name,
+      attributes: {},
+      children: [],
+    };
+    for (const [name, attr] of Object.entries(data.attributes)) {
+      element.attributes[name] = attr.value;
+    }
+    pushToContent(element);
+    current = element;
+    stack.push(element);
+  };
+
+  /**
+   * @type {(text: string) => void}
+   */
+  sax.ontext = (text) => {
+    if (current.type === 'element') {
+      // prevent trimming of meaningful whitespace inside textual tags
+      if (textElems.has(current.name)) {
+        /**
+         * @type {XastText}
+         */
+        const node = {
+          type: 'text',
+          value: text,
+        };
+        pushToContent(node);
+      } else if (/\S/.test(text)) {
+        /**
+         * @type {XastText}
+         */
+        const node = {
+          type: 'text',
+          value: text.trim(),
+        };
+        pushToContent(node);
+      }
+    }
+  };
+
+  sax.onclosetag = () => {
+    stack.pop();
+    current = stack[stack.length - 1];
+  };
+
+  /**
+   * @type {(e: any) => void}
+   */
+  sax.onerror = (e) => {
+    const error = new SvgoParserError(
+      e.reason,
+      e.line + 1,
+      e.column,
+      data,
+      from,
+    );
+    if (e.message.indexOf('Unexpected end') === -1) {
+      throw error;
+    }
+  };
+
+  sax.write(data).close();
+  return root;
+};
+exports.parseSvg = parseSvg;

backend/node_modules/svgo/lib/path.js

@@ -0,0 +1,380 @@
+'use strict';
+
+const { removeLeadingZero, toFixed } = require('./svgo/tools');
+
+/**
+ * @typedef {import('./types').PathDataItem} PathDataItem
+ * @typedef {import('./types').PathDataCommand} PathDataCommand
+ */
+
+// Based on https://www.w3.org/TR/SVG11/paths.html#PathDataBNF
+
+const argsCountPerCommand = {
+  M: 2,
+  m: 2,
+  Z: 0,
+  z: 0,
+  L: 2,
+  l: 2,
+  H: 1,
+  h: 1,
+  V: 1,
+  v: 1,
+  C: 6,
+  c: 6,
+  S: 4,
+  s: 4,
+  Q: 4,
+  q: 4,
+  T: 2,
+  t: 2,
+  A: 7,
+  a: 7,
+};
+
+/**
+ * @type {(c: string) => c is PathDataCommand}
+ */
+const isCommand = (c) => {
+  return c in argsCountPerCommand;
+};
+
+/**
+ * @type {(c: string) => boolean}
+ */
+const isWsp = (c) => {
+  const codePoint = c.codePointAt(0);
+  return (
+    codePoint === 0x20 ||
+    codePoint === 0x9 ||
+    codePoint === 0xd ||
+    codePoint === 0xa
+  );
+};
+
+/**
+ * @type {(c: string) => boolean}
+ */
+const isDigit = (c) => {
+  const codePoint = c.codePointAt(0);
+  if (codePoint == null) {
+    return false;
+  }
+  return 48 <= codePoint && codePoint <= 57;
+};
+
+/**
+ * @typedef {'none' | 'sign' | 'whole' | 'decimal_point' | 'decimal' | 'e' | 'exponent_sign' | 'exponent'} ReadNumberState
+ */
+
+/**
+ * @type {(string: string, cursor: number) => [number, ?number]}
+ */
+const readNumber = (string, cursor) => {
+  let i = cursor;
+  let value = '';
+  let state = /** @type {ReadNumberState} */ ('none');
+  for (; i < string.length; i += 1) {
+    const c = string[i];
+    if (c === '+' || c === '-') {
+      if (state === 'none') {
+        state = 'sign';
+        value += c;
+        continue;
+      }
+      if (state === 'e') {
+        state = 'exponent_sign';
+        value += c;
+        continue;
+      }
+    }
+    if (isDigit(c)) {
+      if (state === 'none' || state === 'sign' || state === 'whole') {
+        state = 'whole';
+        value += c;
+        continue;
+      }
+      if (state === 'decimal_point' || state === 'decimal') {
+        state = 'decimal';
+        value += c;
+        continue;
+      }
+      if (state === 'e' || state === 'exponent_sign' || state === 'exponent') {
+        state = 'exponent';
+        value += c;
+        continue;
+      }
+    }
+    if (c === '.') {
+      if (state === 'none' || state === 'sign' || state === 'whole') {
+        state = 'decimal_point';
+        value += c;
+        continue;
+      }
+    }
+    if (c === 'E' || c == 'e') {
+      if (
+        state === 'whole' ||
+        state === 'decimal_point' ||
+        state === 'decimal'
+      ) {
+        state = 'e';
+        value += c;
+        continue;
+      }
+    }
+    break;
+  }
+  const number = Number.parseFloat(value);
+  if (Number.isNaN(number)) {
+    return [cursor, null];
+  } else {
+    // step back to delegate iteration to parent loop
+    return [i - 1, number];
+  }
+};
+
+/**
+ * @type {(string: string) => PathDataItem[]}
+ */
+const parsePathData = (string) => {
+  /**
+   * @type {PathDataItem[]}
+   */
+  const pathData = [];
+  /**
+   * @type {?PathDataCommand}
+   */
+  let command = null;
+  let args = /** @type {number[]} */ ([]);
+  let argsCount = 0;
+  let canHaveComma = false;
+  let hadComma = false;
+  for (let i = 0; i < string.length; i += 1) {
+    const c = string.charAt(i);
+    if (isWsp(c)) {
+      continue;
+    }
+    // allow comma only between arguments
+    if (canHaveComma && c === ',') {
+      if (hadComma) {
+        break;
+      }
+      hadComma = true;
+      continue;
+    }
+    if (isCommand(c)) {
+      if (hadComma) {
+        return pathData;
+      }
+      if (command == null) {
+        // moveto should be leading command
+        if (c !== 'M' && c !== 'm') {
+          return pathData;
+        }
+      } else {
+        // stop if previous command arguments are not flushed
+        if (args.length !== 0) {
+          return pathData;
+        }
+      }
+      command = c;
+      args = [];
+      argsCount = argsCountPerCommand[command];
+      canHaveComma = false;
+      // flush command without arguments
+      if (argsCount === 0) {
+        pathData.push({ command, args });
+      }
+      continue;
+    }
+    // avoid parsing arguments if no command detected
+    if (command == null) {
+      return pathData;
+    }
+    // read next argument
+    let newCursor = i;
+    let number = null;
+    if (command === 'A' || command === 'a') {
+      const position = args.length;
+      if (position === 0 || position === 1) {
+        // allow only positive number without sign as first two arguments
+        if (c !== '+' && c !== '-') {
+          [newCursor, number] = readNumber(string, i);
+        }
+      }
+      if (position === 2 || position === 5 || position === 6) {
+        [newCursor, number] = readNumber(string, i);
+      }
+      if (position === 3 || position === 4) {
+        // read flags
+        if (c === '0') {
+          number = 0;
+        }
+        if (c === '1') {
+          number = 1;
+        }
+      }
+    } else {
+      [newCursor, number] = readNumber(string, i);
+    }
+    if (number == null) {
+      return pathData;
+    }
+    args.push(number);
+    canHaveComma = true;
+    hadComma = false;
+    i = newCursor;
+    // flush arguments when necessary count is reached
+    if (args.length === argsCount) {
+      pathData.push({ command, args });
+      // subsequent moveto coordinates are treated as implicit lineto commands
+      if (command === 'M') {
+        command = 'L';
+      }
+      if (command === 'm') {
+        command = 'l';
+      }
+      args = [];
+    }
+  }
+  return pathData;
+};
+exports.parsePathData = parsePathData;
+
+/**
+ * @type {(number: number, precision?: number) => {
+ *   roundedStr: string,
+ *   rounded: number
+ * }}
+ */
+const roundAndStringify = (number, precision) => {
+  if (precision != null) {
+    number = toFixed(number, precision);
+  }
+
+  return {
+    roundedStr: removeLeadingZero(number),
+    rounded: number,
+  };
+};
+
+/**
+ * Elliptical arc large-arc and sweep flags are rendered with spaces
+ * because many non-browser environments are not able to parse such paths
+ *
+ * @type {(
+ *   command: string,
+ *   args: number[],
+ *   precision?: number,
+ *   disableSpaceAfterFlags?: boolean
+ * ) => string}
+ */
+const stringifyArgs = (command, args, precision, disableSpaceAfterFlags) => {
+  let result = '';
+  let previous;
+
+  for (let i = 0; i < args.length; i++) {
+    const { roundedStr, rounded } = roundAndStringify(args[i], precision);
+    if (
+      disableSpaceAfterFlags &&
+      (command === 'A' || command === 'a') &&
+      // consider combined arcs
+      (i % 7 === 4 || i % 7 === 5)
+    ) {
+      result += roundedStr;
+    } else if (i === 0 || rounded < 0) {
+      // avoid space before first and negative numbers
+      result += roundedStr;
+    } else if (
+      !Number.isInteger(previous) &&
+      rounded != 0 &&
+      rounded < 1 &&
+      rounded > -1
+    ) {
+      // remove space before decimal with zero whole
+      // only when previous number is also decimal
+      result += roundedStr;
+    } else {
+      result += ` ${roundedStr}`;
+    }
+    previous = rounded;
+  }
+
+  return result;
+};
+
+/**
+ * @typedef {{
+ *   pathData: PathDataItem[];
+ *   precision?: number;
+ *   disableSpaceAfterFlags?: boolean;
+ * }} StringifyPathDataOptions
+ */
+
+/**
+ * @param {StringifyPathDataOptions} options
+ * @returns {string}
+ */
+const stringifyPathData = ({ pathData, precision, disableSpaceAfterFlags }) => {
+  if (pathData.length === 1) {
+    const { command, args } = pathData[0];
+    return (
+      command + stringifyArgs(command, args, precision, disableSpaceAfterFlags)
+    );
+  }
+
+  let result = '';
+  let prev = { ...pathData[0] };
+
+  // match leading moveto with following lineto
+  if (pathData[1].command === 'L') {
+    prev.command = 'M';
+  } else if (pathData[1].command === 'l') {
+    prev.command = 'm';
+  }
+
+  for (let i = 1; i < pathData.length; i++) {
+    const { command, args } = pathData[i];
+    if (
+      (prev.command === command &&
+        prev.command !== 'M' &&
+        prev.command !== 'm') ||
+      // combine matching moveto and lineto sequences
+      (prev.command === 'M' && command === 'L') ||
+      (prev.command === 'm' && command === 'l')
+    ) {
+      prev.args = [...prev.args, ...args];
+      if (i === pathData.length - 1) {
+        result +=
+          prev.command +
+          stringifyArgs(
+            prev.command,
+            prev.args,
+            precision,
+            disableSpaceAfterFlags,
+          );
+      }
+    } else {
+      result +=
+        prev.command +
+        stringifyArgs(
+          prev.command,
+          prev.args,
+          precision,
+          disableSpaceAfterFlags,
+        );
+
+      if (i === pathData.length - 1) {
+        result +=
+          command +
+          stringifyArgs(command, args, precision, disableSpaceAfterFlags);
+      } else {
+        prev = { command, args };
+      }
+    }
+  }
+
+  return result;
+};
+exports.stringifyPathData = stringifyPathData;

backend/node_modules/svgo/lib/stringifier.js

@@ -0,0 +1,295 @@
+'use strict';
+
+/**
+ * @typedef {import('./types').XastParent} XastParent
+ * @typedef {import('./types').XastRoot} XastRoot
+ * @typedef {import('./types').XastElement} XastElement
+ * @typedef {import('./types').XastInstruction} XastInstruction
+ * @typedef {import('./types').XastDoctype} XastDoctype
+ * @typedef {import('./types').XastText} XastText
+ * @typedef {import('./types').XastCdata} XastCdata
+ * @typedef {import('./types').XastComment} XastComment
+ * @typedef {import('./types').StringifyOptions} StringifyOptions
+ */
+
+const { textElems } = require('../plugins/_collections');
+
+/**
+ * @typedef {{
+ *   indent: string,
+ *   textContext: ?XastElement,
+ *   indentLevel: number,
+ * }} State
+ */
+
+/**
+ * @typedef {Required<StringifyOptions>} Options
+ */
+
+/**
+ * @type {(char: string) => string}
+ */
+const encodeEntity = (char) => {
+  return entities[char];
+};
+
+/** @type {Options} */
+const defaults = {
+  doctypeStart: '<!DOCTYPE',
+  doctypeEnd: '>',
+  procInstStart: '<?',
+  procInstEnd: '?>',
+  tagOpenStart: '<',
+  tagOpenEnd: '>',
+  tagCloseStart: '</',
+  tagCloseEnd: '>',
+  tagShortStart: '<',
+  tagShortEnd: '/>',
+  attrStart: '="',
+  attrEnd: '"',
+  commentStart: '<!--',
+  commentEnd: '-->',
+  cdataStart: '<![CDATA[',
+  cdataEnd: ']]>',
+  textStart: '',
+  textEnd: '',
+  indent: 4,
+  regEntities: /[&'"<>]/g,
+  regValEntities: /[&"<>]/g,
+  encodeEntity,
+  pretty: false,
+  useShortTags: true,
+  eol: 'lf',
+  finalNewline: false,
+};
+
+/** @type {Record<string, string>} */
+const entities = {
+  '&': '&amp;',
+  "'": '&apos;',
+  '"': '&quot;',
+  '>': '&gt;',
+  '<': '&lt;',
+};
+
+/**
+ * convert XAST to SVG string
+ *
+ * @type {(data: XastRoot, config: StringifyOptions) => string}
+ */
+const stringifySvg = (data, userOptions = {}) => {
+  /**
+   * @type {Options}
+   */
+  const config = { ...defaults, ...userOptions };
+  const indent = config.indent;
+  let newIndent = '    ';
+  if (typeof indent === 'number' && Number.isNaN(indent) === false) {
+    newIndent = indent < 0 ? '\t' : ' '.repeat(indent);
+  } else if (typeof indent === 'string') {
+    newIndent = indent;
+  }
+  /**
+   * @type {State}
+   */
+  const state = {
+    indent: newIndent,
+    textContext: null,
+    indentLevel: 0,
+  };
+  const eol = config.eol === 'crlf' ? '\r\n' : '\n';
+  if (config.pretty) {
+    config.doctypeEnd += eol;
+    config.procInstEnd += eol;
+    config.commentEnd += eol;
+    config.cdataEnd += eol;
+    config.tagShortEnd += eol;
+    config.tagOpenEnd += eol;
+    config.tagCloseEnd += eol;
+    config.textEnd += eol;
+  }
+  let svg = stringifyNode(data, config, state);
+  if (config.finalNewline && svg.length > 0 && !svg.endsWith('\n')) {
+    svg += eol;
+  }
+  return svg;
+};
+exports.stringifySvg = stringifySvg;
+
+/**
+ * @type {(node: XastParent, config: Options, state: State) => string}
+ */
+const stringifyNode = (data, config, state) => {
+  let svg = '';
+  state.indentLevel += 1;
+  for (const item of data.children) {
+    if (item.type === 'element') {
+      svg += stringifyElement(item, config, state);
+    }
+    if (item.type === 'text') {
+      svg += stringifyText(item, config, state);
+    }
+    if (item.type === 'doctype') {
+      svg += stringifyDoctype(item, config);
+    }
+    if (item.type === 'instruction') {
+      svg += stringifyInstruction(item, config);
+    }
+    if (item.type === 'comment') {
+      svg += stringifyComment(item, config);
+    }
+    if (item.type === 'cdata') {
+      svg += stringifyCdata(item, config, state);
+    }
+  }
+  state.indentLevel -= 1;
+  return svg;
+};
+
+/**
+ * create indent string in accordance with the current node level.
+ *
+ * @type {(config: Options, state: State) => string}
+ */
+const createIndent = (config, state) => {
+  let indent = '';
+  if (config.pretty && state.textContext == null) {
+    indent = state.indent.repeat(state.indentLevel - 1);
+  }
+  return indent;
+};
+
+/**
+ * @type {(node: XastDoctype, config: Options) => string}
+ */
+const stringifyDoctype = (node, config) => {
+  return config.doctypeStart + node.data.doctype + config.doctypeEnd;
+};
+
+/**
+ * @type {(node: XastInstruction, config: Options) => string}
+ */
+const stringifyInstruction = (node, config) => {
+  return (
+    config.procInstStart + node.name + ' ' + node.value + config.procInstEnd
+  );
+};
+
+/**
+ * @type {(node: XastComment, config: Options) => string}
+ */
+const stringifyComment = (node, config) => {
+  return config.commentStart + node.value + config.commentEnd;
+};
+
+/**
+ * @type {(node: XastCdata, config: Options, state: State) => string}
+ */
+const stringifyCdata = (node, config, state) => {
+  return (
+    createIndent(config, state) +
+    config.cdataStart +
+    node.value +
+    config.cdataEnd
+  );
+};
+
+/**
+ * @type {(node: XastElement, config: Options, state: State) => string}
+ */
+const stringifyElement = (node, config, state) => {
+  // empty element and short tag
+  if (node.children.length === 0) {
+    if (config.useShortTags) {
+      return (
+        createIndent(config, state) +
+        config.tagShortStart +
+        node.name +
+        stringifyAttributes(node, config) +
+        config.tagShortEnd
+      );
+    } else {
+      return (
+        createIndent(config, state) +
+        config.tagShortStart +
+        node.name +
+        stringifyAttributes(node, config) +
+        config.tagOpenEnd +
+        config.tagCloseStart +
+        node.name +
+        config.tagCloseEnd
+      );
+    }
+    // non-empty element
+  } else {
+    let tagOpenStart = config.tagOpenStart;
+    let tagOpenEnd = config.tagOpenEnd;
+    let tagCloseStart = config.tagCloseStart;
+    let tagCloseEnd = config.tagCloseEnd;
+    let openIndent = createIndent(config, state);
+    let closeIndent = createIndent(config, state);
+
+    if (state.textContext) {
+      tagOpenStart = defaults.tagOpenStart;
+      tagOpenEnd = defaults.tagOpenEnd;
+      tagCloseStart = defaults.tagCloseStart;
+      tagCloseEnd = defaults.tagCloseEnd;
+      openIndent = '';
+    } else if (textElems.has(node.name)) {
+      tagOpenEnd = defaults.tagOpenEnd;
+      tagCloseStart = defaults.tagCloseStart;
+      closeIndent = '';
+      state.textContext = node;
+    }
+
+    const children = stringifyNode(node, config, state);
+
+    if (state.textContext === node) {
+      state.textContext = null;
+    }
+
+    return (
+      openIndent +
+      tagOpenStart +
+      node.name +
+      stringifyAttributes(node, config) +
+      tagOpenEnd +
+      children +
+      closeIndent +
+      tagCloseStart +
+      node.name +
+      tagCloseEnd
+    );
+  }
+};
+
+/**
+ * @type {(node: XastElement, config: Options) => string}
+ */
+const stringifyAttributes = (node, config) => {
+  let attrs = '';
+  for (const [name, value] of Object.entries(node.attributes)) {
+    // TODO remove attributes without values support in v3
+    if (value !== undefined) {
+      const encodedValue = value
+        .toString()
+        .replace(config.regValEntities, config.encodeEntity);
+      attrs += ' ' + name + config.attrStart + encodedValue + config.attrEnd;
+    } else {
+      attrs += ' ' + name;
+    }
+  }
+  return attrs;
+};
+
+/**
+ * @type {(node: XastText, config: Options, state: State) => string}
+ */
+const stringifyText = (node, config, state) => {
+  return (
+    createIndent(config, state) +
+    config.textStart +
+    node.value.replace(config.regEntities, config.encodeEntity) +
+    (state.textContext ? '' : config.textEnd)
+  );
+};

backend/node_modules/svgo/lib/style.js

@@ -0,0 +1,336 @@
+'use strict';
+
+/**
+ * @typedef {import('css-tree').Rule} CsstreeRule
+ * @typedef {import('./types').Specificity} Specificity
+ * @typedef {import('./types').Stylesheet} Stylesheet
+ * @typedef {import('./types').StylesheetRule} StylesheetRule
+ * @typedef {import('./types').StylesheetDeclaration} StylesheetDeclaration
+ * @typedef {import('./types').ComputedStyles} ComputedStyles
+ * @typedef {import('./types').XastRoot} XastRoot
+ * @typedef {import('./types').XastElement} XastElement
+ * @typedef {import('./types').XastParent} XastParent
+ * @typedef {import('./types').XastChild} XastChild
+ */
+
+const csstree = require('css-tree');
+const csswhat = require('css-what');
+const {
+  syntax: { specificity },
+} = require('csso');
+const { visit, matches } = require('./xast.js');
+const {
+  attrsGroups,
+  inheritableAttrs,
+  presentationNonInheritableGroupAttrs,
+} = require('../plugins/_collections.js');
+
+// @ts-ignore not defined in @types/csstree
+const csstreeWalkSkip = csstree.walk.skip;
+
+/**
+ * @type {(ruleNode: CsstreeRule, dynamic: boolean) => StylesheetRule[]}
+ */
+const parseRule = (ruleNode, dynamic) => {
+  /**
+   * @type {StylesheetDeclaration[]}
+   */
+  const declarations = [];
+  // collect declarations
+  ruleNode.block.children.forEach((cssNode) => {
+    if (cssNode.type === 'Declaration') {
+      declarations.push({
+        name: cssNode.property,
+        value: csstree.generate(cssNode.value),
+        important: cssNode.important === true,
+      });
+    }
+  });
+
+  /** @type {StylesheetRule[]} */
+  const rules = [];
+  csstree.walk(ruleNode.prelude, (node) => {
+    if (node.type === 'Selector') {
+      const newNode = csstree.clone(node);
+      let hasPseudoClasses = false;
+      csstree.walk(newNode, (pseudoClassNode, item, list) => {
+        if (pseudoClassNode.type === 'PseudoClassSelector') {
+          hasPseudoClasses = true;
+          list.remove(item);
+        }
+      });
+      rules.push({
+        specificity: specificity(node),
+        dynamic: hasPseudoClasses || dynamic,
+        // compute specificity from original node to consider pseudo classes
+        selector: csstree.generate(newNode),
+        declarations,
+      });
+    }
+  });
+
+  return rules;
+};
+
+/**
+ * @type {(css: string, dynamic: boolean) => StylesheetRule[]}
+ */
+const parseStylesheet = (css, dynamic) => {
+  /** @type {StylesheetRule[]} */
+  const rules = [];
+  const ast = csstree.parse(css, {
+    parseValue: false,
+    parseAtrulePrelude: false,
+  });
+  csstree.walk(ast, (cssNode) => {
+    if (cssNode.type === 'Rule') {
+      rules.push(...parseRule(cssNode, dynamic || false));
+      return csstreeWalkSkip;
+    }
+    if (cssNode.type === 'Atrule') {
+      if (
+        cssNode.name === 'keyframes' ||
+        cssNode.name === '-webkit-keyframes'
+      ) {
+        return csstreeWalkSkip;
+      }
+      csstree.walk(cssNode, (ruleNode) => {
+        if (ruleNode.type === 'Rule') {
+          rules.push(...parseRule(ruleNode, dynamic || true));
+          return csstreeWalkSkip;
+        }
+      });
+      return csstreeWalkSkip;
+    }
+  });
+  return rules;
+};
+
+/**
+ * @type {(css: string) => StylesheetDeclaration[]}
+ */
+const parseStyleDeclarations = (css) => {
+  /** @type {StylesheetDeclaration[]} */
+  const declarations = [];
+  const ast = csstree.parse(css, {
+    context: 'declarationList',
+    parseValue: false,
+  });
+  csstree.walk(ast, (cssNode) => {
+    if (cssNode.type === 'Declaration') {
+      declarations.push({
+        name: cssNode.property,
+        value: csstree.generate(cssNode.value),
+        important: cssNode.important === true,
+      });
+    }
+  });
+  return declarations;
+};
+
+/**
+ * @param {Stylesheet} stylesheet
+ * @param {XastElement} node
+ * @returns {ComputedStyles}
+ */
+const computeOwnStyle = (stylesheet, node) => {
+  /** @type {ComputedStyles} */
+  const computedStyle = {};
+  const importantStyles = new Map();
+
+  // collect attributes
+  for (const [name, value] of Object.entries(node.attributes)) {
+    if (attrsGroups.presentation.has(name)) {
+      computedStyle[name] = { type: 'static', inherited: false, value };
+      importantStyles.set(name, false);
+    }
+  }
+
+  // collect matching rules
+  for (const { selector, declarations, dynamic } of stylesheet.rules) {
+    if (matches(node, selector)) {
+      for (const { name, value, important } of declarations) {
+        const computed = computedStyle[name];
+        if (computed && computed.type === 'dynamic') {
+          continue;
+        }
+        if (dynamic) {
+          computedStyle[name] = { type: 'dynamic', inherited: false };
+          continue;
+        }
+        if (
+          computed == null ||
+          important === true ||
+          importantStyles.get(name) === false
+        ) {
+          computedStyle[name] = { type: 'static', inherited: false, value };
+          importantStyles.set(name, important);
+        }
+      }
+    }
+  }
+
+  // collect inline styles
+  const styleDeclarations =
+    node.attributes.style == null
+      ? []
+      : parseStyleDeclarations(node.attributes.style);
+  for (const { name, value, important } of styleDeclarations) {
+    const computed = computedStyle[name];
+    if (computed && computed.type === 'dynamic') {
+      continue;
+    }
+    if (
+      computed == null ||
+      important === true ||
+      importantStyles.get(name) === false
+    ) {
+      computedStyle[name] = { type: 'static', inherited: false, value };
+      importantStyles.set(name, important);
+    }
+  }
+
+  return computedStyle;
+};
+
+/**
+ * Compares selector specificities.
+ * Derived from https://github.com/keeganstreet/specificity/blob/8757133ddd2ed0163f120900047ff0f92760b536/specificity.js#L207
+ *
+ * @param {Specificity} a
+ * @param {Specificity} b
+ * @returns {number}
+ */
+const compareSpecificity = (a, b) => {
+  for (let i = 0; i < 4; i += 1) {
+    if (a[i] < b[i]) {
+      return -1;
+    } else if (a[i] > b[i]) {
+      return 1;
+    }
+  }
+
+  return 0;
+};
+exports.compareSpecificity = compareSpecificity;
+
+/**
+ * @type {(root: XastRoot) => Stylesheet}
+ */
+const collectStylesheet = (root) => {
+  /** @type {StylesheetRule[]} */
+  const rules = [];
+  /** @type {Map<XastElement, XastParent>} */
+  const parents = new Map();
+
+  visit(root, {
+    element: {
+      enter: (node, parentNode) => {
+        parents.set(node, parentNode);
+
+        if (node.name !== 'style') {
+          return;
+        }
+
+        if (
+          node.attributes.type == null ||
+          node.attributes.type === '' ||
+          node.attributes.type === 'text/css'
+        ) {
+          const dynamic =
+            node.attributes.media != null && node.attributes.media !== 'all';
+
+          for (const child of node.children) {
+            if (child.type === 'text' || child.type === 'cdata') {
+              rules.push(...parseStylesheet(child.value, dynamic));
+            }
+          }
+        }
+      },
+    },
+  });
+  // sort by selectors specificity
+  rules.sort((a, b) => compareSpecificity(a.specificity, b.specificity));
+  return { rules, parents };
+};
+exports.collectStylesheet = collectStylesheet;
+
+/**
+ * @param {Stylesheet} stylesheet
+ * @param {XastElement} node
+ * @returns {ComputedStyles}
+ */
+const computeStyle = (stylesheet, node) => {
+  const { parents } = stylesheet;
+  const computedStyles = computeOwnStyle(stylesheet, node);
+  let parent = parents.get(node);
+  while (parent != null && parent.type !== 'root') {
+    const inheritedStyles = computeOwnStyle(stylesheet, parent);
+    for (const [name, computed] of Object.entries(inheritedStyles)) {
+      if (
+        computedStyles[name] == null &&
+        inheritableAttrs.has(name) &&
+        !presentationNonInheritableGroupAttrs.has(name)
+      ) {
+        computedStyles[name] = { ...computed, inherited: true };
+      }
+    }
+    parent = parents.get(parent);
+  }
+  return computedStyles;
+};
+exports.computeStyle = computeStyle;
+
+/**
+ * Determines if the CSS selector includes or traverses the given attribute.
+ *
+ * Classes and IDs are generated as attribute selectors, so you can check for
+ * if a `.class` or `#id` is included by passing `name=class` or `name=id`
+ * respectively.
+ *
+ * @param {csstree.ListItem<csstree.CssNode>|string} selector
+ * @param {string} name
+ * @param {?string} value
+ * @param {boolean} traversed
+ * @returns {boolean}
+ */
+const includesAttrSelector = (
+  selector,
+  name,
+  value = null,
+  traversed = false,
+) => {
+  const selectors =
+    typeof selector === 'string'
+      ? csswhat.parse(selector)
+      : csswhat.parse(csstree.generate(selector.data));
+
+  for (const subselector of selectors) {
+    const hasAttrSelector = subselector.some((segment, index) => {
+      if (traversed) {
+        if (index === subselector.length - 1) {
+          return false;
+        }
+
+        const isNextTraversal = csswhat.isTraversal(subselector[index + 1]);
+
+        if (!isNextTraversal) {
+          return false;
+        }
+      }
+
+      if (segment.type !== 'attribute' || segment.name !== name) {
+        return false;
+      }
+
+      return value == null ? true : segment.value === value;
+    });
+
+    if (hasAttrSelector) {
+      return true;
+    }
+  }
+
+  return false;
+};
+exports.includesAttrSelector = includesAttrSelector;

backend/node_modules/svgo/lib/svgo-node.js

@@ -0,0 +1,85 @@
+'use strict';
+
+const os = require('os');
+const fs = require('fs');
+const { pathToFileURL } = require('url');
+const path = require('path');
+const { optimize: optimizeAgnostic } = require('./svgo.js');
+
+const importConfig = async (configFile) => {
+  let config;
+  // at the moment dynamic import may randomly fail with segfault
+  // to workaround this for some users .cjs extension is loaded
+  // exclusively with require
+  if (configFile.endsWith('.cjs')) {
+    config = require(configFile);
+  } else {
+    // dynamic import expects file url instead of path and may fail
+    // when windows path is provided
+    const { default: imported } = await import(pathToFileURL(configFile));
+    config = imported;
+  }
+  if (config == null || typeof config !== 'object' || Array.isArray(config)) {
+    throw Error(`Invalid config file "${configFile}"`);
+  }
+  return config;
+};
+
+const isFile = async (file) => {
+  try {
+    const stats = await fs.promises.stat(file);
+    return stats.isFile();
+  } catch {
+    return false;
+  }
+};
+
+const loadConfig = async (configFile, cwd = process.cwd()) => {
+  if (configFile != null) {
+    if (path.isAbsolute(configFile)) {
+      return await importConfig(configFile);
+    } else {
+      return await importConfig(path.join(cwd, configFile));
+    }
+  }
+  let dir = cwd;
+  // eslint-disable-next-line no-constant-condition
+  while (true) {
+    const js = path.join(dir, 'svgo.config.js');
+    if (await isFile(js)) {
+      return await importConfig(js);
+    }
+    const mjs = path.join(dir, 'svgo.config.mjs');
+    if (await isFile(mjs)) {
+      return await importConfig(mjs);
+    }
+    const cjs = path.join(dir, 'svgo.config.cjs');
+    if (await isFile(cjs)) {
+      return await importConfig(cjs);
+    }
+    const parent = path.dirname(dir);
+    if (dir === parent) {
+      return null;
+    }
+    dir = parent;
+  }
+};
+exports.loadConfig = loadConfig;
+
+const optimize = (input, config) => {
+  if (config == null) {
+    config = {};
+  }
+  if (typeof config !== 'object') {
+    throw Error('Config should be an object');
+  }
+  return optimizeAgnostic(input, {
+    ...config,
+    js2svg: {
+      // platform specific default for end of line
+      eol: os.EOL === '\r\n' ? 'crlf' : 'lf',
+      ...config.js2svg,
+    },
+  });
+};
+exports.optimize = optimize;

backend/node_modules/svgo/lib/svgo.d.ts

@@ -0,0 +1,69 @@
+import type { StringifyOptions, DataUri, Plugin as PluginFn } from './types';
+import type {
+  BuiltinsWithOptionalParams,
+  BuiltinsWithRequiredParams,
+} from '../plugins/plugins-types';
+
+type CustomPlugin = {
+  name: string;
+  fn: PluginFn<void>;
+};
+
+type PluginConfig =
+  | keyof BuiltinsWithOptionalParams
+  | {
+      [Name in keyof BuiltinsWithOptionalParams]: {
+        name: Name;
+        params?: BuiltinsWithOptionalParams[Name];
+      };
+    }[keyof BuiltinsWithOptionalParams]
+  | {
+      [Name in keyof BuiltinsWithRequiredParams]: {
+        name: Name;
+        params: BuiltinsWithRequiredParams[Name];
+      };
+    }[keyof BuiltinsWithRequiredParams]
+  | CustomPlugin;
+
+export type Config = {
+  /** Can be used by plugins, for example prefixids */
+  path?: string;
+  /** Pass over SVGs multiple times to ensure all optimizations are applied. */
+  multipass?: boolean;
+  /** Precision of floating point numbers. Will be passed to each plugin that supports this param. */
+  floatPrecision?: number;
+  /**
+   * Plugins configuration
+   * ['preset-default'] is default
+   * Can also specify any builtin plugin
+   * ['sortAttrs', { name: 'prefixIds', params: { prefix: 'my-prefix' } }]
+   * Or custom
+   * [{ name: 'myPlugin', fn: () => ({}) }]
+   */
+  plugins?: PluginConfig[];
+  /** Options for rendering optimized SVG from AST. */
+  js2svg?: StringifyOptions;
+  /** Output as Data URI string. */
+  datauri?: DataUri;
+};
+
+type Output = {
+  data: string;
+};
+
+/** The core of SVGO */
+export declare function optimize(input: string, config?: Config): Output;
+
+/**
+ * If you write a tool on top of svgo you might need a way to load svgo config.
+ *
+ * You can also specify relative or absolute path and customize current working directory.
+ */
+export declare function loadConfig(
+  configFile: string,
+  cwd?: string,
+): Promise<Config>;
+export declare function loadConfig(
+  configFile?: null,
+  cwd?: string,
+): Promise<Config | null>;

backend/node_modules/svgo/lib/svgo.js

@@ -0,0 +1,102 @@
+'use strict';
+
+const { parseSvg } = require('./parser.js');
+const { stringifySvg } = require('./stringifier.js');
+const { builtin } = require('./builtin.js');
+const { invokePlugins } = require('./svgo/plugins.js');
+const { encodeSVGDatauri } = require('./svgo/tools.js');
+
+const pluginsMap = {};
+for (const plugin of builtin) {
+  pluginsMap[plugin.name] = plugin;
+}
+
+const resolvePluginConfig = (plugin) => {
+  if (typeof plugin === 'string') {
+    // resolve builtin plugin specified as string
+    const builtinPlugin = pluginsMap[plugin];
+    if (builtinPlugin == null) {
+      throw Error(`Unknown builtin plugin "${plugin}" specified.`);
+    }
+    return {
+      name: plugin,
+      params: {},
+      fn: builtinPlugin.fn,
+    };
+  }
+  if (typeof plugin === 'object' && plugin != null) {
+    if (plugin.name == null) {
+      throw Error(`Plugin name should be specified`);
+    }
+    // use custom plugin implementation
+    let fn = plugin.fn;
+    if (fn == null) {
+      // resolve builtin plugin implementation
+      const builtinPlugin = pluginsMap[plugin.name];
+      if (builtinPlugin == null) {
+        throw Error(`Unknown builtin plugin "${plugin.name}" specified.`);
+      }
+      fn = builtinPlugin.fn;
+    }
+    return {
+      name: plugin.name,
+      params: plugin.params,
+      fn,
+    };
+  }
+  return null;
+};
+
+const optimize = (input, config) => {
+  if (config == null) {
+    config = {};
+  }
+  if (typeof config !== 'object') {
+    throw Error('Config should be an object');
+  }
+  const maxPassCount = config.multipass ? 10 : 1;
+  let prevResultSize = Number.POSITIVE_INFINITY;
+  let output = '';
+  const info = {};
+  if (config.path != null) {
+    info.path = config.path;
+  }
+  for (let i = 0; i < maxPassCount; i += 1) {
+    info.multipassCount = i;
+    const ast = parseSvg(input, config.path);
+    const plugins = config.plugins || ['preset-default'];
+    if (!Array.isArray(plugins)) {
+      throw Error(
+        'malformed config, `plugins` property must be an array.\nSee more info here: https://github.com/svg/svgo#configuration',
+      );
+    }
+    const resolvedPlugins = plugins
+      .filter((plugin) => plugin != null)
+      .map(resolvePluginConfig);
+
+    if (resolvedPlugins.length < plugins.length) {
+      console.warn(
+        'Warning: plugins list includes null or undefined elements, these will be ignored.',
+      );
+    }
+    const globalOverrides = {};
+    if (config.floatPrecision != null) {
+      globalOverrides.floatPrecision = config.floatPrecision;
+    }
+    invokePlugins(ast, info, resolvedPlugins, null, globalOverrides);
+    output = stringifySvg(ast, config.js2svg);
+    if (output.length < prevResultSize) {
+      input = output;
+      prevResultSize = output.length;
+    } else {
+      break;
+    }
+  }
+  if (config.datauri) {
+    output = encodeSVGDatauri(output, config.datauri);
+  }
+  return {
+    data: output,
+  };
+};
+exports.optimize = optimize;

backend/node_modules/svgo/lib/svgo/coa.js

@@ -0,0 +1,528 @@
+'use strict';
+
+const fs = require('fs');
+const path = require('path');
+const colors = require('picocolors');
+const { loadConfig, optimize } = require('../svgo-node.js');
+const { builtin } = require('../builtin.js');
+const PKG = require('../../package.json');
+const { encodeSVGDatauri, decodeSVGDatauri } = require('./tools.js');
+
+const regSVGFile = /\.svg$/i;
+
+/**
+ * Synchronously check if path is a directory. Tolerant to errors like ENOENT.
+ *
+ * @param {string} path
+ */
+function checkIsDir(path) {
+  try {
+    return fs.lstatSync(path).isDirectory();
+  } catch (e) {
+    return false;
+  }
+}
+
+module.exports = function makeProgram(program) {
+  program
+    .name(PKG.name)
+    .description(PKG.description, {
+      INPUT: 'Alias to --input',
+    })
+    .version(PKG.version, '-v, --version')
+    .arguments('[INPUT...]')
+    .option('-i, --input <INPUT...>', 'Input files, "-" for STDIN')
+    .option('-s, --string <STRING>', 'Input SVG data string')
+    .option(
+      '-f, --folder <FOLDER>',
+      'Input folder, optimize and rewrite all *.svg files',
+    )
+    .option(
+      '-o, --output <OUTPUT...>',
+      'Output file or folder (by default the same as the input), "-" for STDOUT',
+    )
+    .option(
+      '-p, --precision <INTEGER>',
+      'Set number of digits in the fractional part, overrides plugins params',
+    )
+    .option('--config <CONFIG>', 'Custom config file, only .js is supported')
+    .option(
+      '--datauri <FORMAT>',
+      'Output as Data URI string (base64), URI encoded (enc) or unencoded (unenc)',
+    )
+    .option(
+      '--multipass',
+      'Pass over SVGs multiple times to ensure all optimizations are applied',
+    )
+    .option('--pretty', 'Make SVG pretty printed')
+    .option('--indent <INTEGER>', 'Indent number when pretty printing SVGs')
+    .option(
+      '--eol <EOL>',
+      'Line break to use when outputting SVG: lf, crlf. If unspecified, uses platform default.',
+    )
+    .option('--final-newline', 'Ensure SVG ends with a line break')
+    .option(
+      '-r, --recursive',
+      "Use with '--folder'. Optimizes *.svg files in folders recursively.",
+    )
+    .option(
+      '--exclude <PATTERN...>',
+      "Use with '--folder'. Exclude files matching regular expression pattern.",
+    )
+    .option(
+      '-q, --quiet',
+      'Only output error messages, not regular status messages',
+    )
+    .option('--show-plugins', 'Show available plugins and exit')
+    // used by picocolors internally
+    .option('--no-color', 'Output plain text without color')
+    .action(action);
+};
+
+async function action(args, opts, command) {
+  var input = opts.input || args;
+  var output = opts.output;
+  var config = {};
+
+  if (opts.precision != null) {
+    const number = Number.parseInt(opts.precision, 10);
+    if (Number.isNaN(number)) {
+      console.error(
+        "error: option '-p, --precision' argument must be an integer number",
+      );
+      process.exit(1);
+    } else {
+      opts.precision = number;
+    }
+  }
+
+  if (opts.datauri != null) {
+    if (
+      opts.datauri !== 'base64' &&
+      opts.datauri !== 'enc' &&
+      opts.datauri !== 'unenc'
+    ) {
+      console.error(
+        "error: option '--datauri' must have one of the following values: 'base64', 'enc' or 'unenc'",
+      );
+      process.exit(1);
+    }
+  }
+
+  if (opts.indent != null) {
+    const number = Number.parseInt(opts.indent, 10);
+    if (Number.isNaN(number)) {
+      console.error(
+        "error: option '--indent' argument must be an integer number",
+      );
+      process.exit(1);
+    } else {
+      opts.indent = number;
+    }
+  }
+
+  if (opts.eol != null && opts.eol !== 'lf' && opts.eol !== 'crlf') {
+    console.error(
+      "error: option '--eol' must have one of the following values: 'lf' or 'crlf'",
+    );
+    process.exit(1);
+  }
+
+  // --show-plugins
+  if (opts.showPlugins) {
+    showAvailablePlugins();
+    return;
+  }
+
+  // w/o anything
+  if (
+    (input.length === 0 || input[0] === '-') &&
+    !opts.string &&
+    !opts.stdin &&
+    !opts.folder &&
+    process.stdin.isTTY === true
+  ) {
+    return command.help();
+  }
+
+  if (
+    typeof process == 'object' &&
+    process.versions &&
+    process.versions.node &&
+    PKG &&
+    PKG.engines.node
+  ) {
+    var nodeVersion = String(PKG.engines.node).match(/\d*(\.\d+)*/)[0];
+    if (parseFloat(process.versions.node) < parseFloat(nodeVersion)) {
+      throw Error(
+        `${PKG.name} requires Node.js version ${nodeVersion} or higher.`,
+      );
+    }
+  }
+
+  // --config
+  const loadedConfig = await loadConfig(opts.config);
+  if (loadedConfig != null) {
+    config = loadedConfig;
+  }
+
+  // --quiet
+  if (opts.quiet) {
+    config.quiet = opts.quiet;
+  }
+
+  // --recursive
+  if (opts.recursive) {
+    config.recursive = opts.recursive;
+  }
+
+  // --exclude
+  config.exclude = opts.exclude
+    ? opts.exclude.map((pattern) => RegExp(pattern))
+    : [];
+
+  // --precision
+  if (opts.precision != null) {
+    var precision = Math.min(Math.max(0, opts.precision), 20);
+    config.floatPrecision = precision;
+  }
+
+  // --multipass
+  if (opts.multipass) {
+    config.multipass = true;
+  }
+
+  // --pretty
+  if (opts.pretty) {
+    config.js2svg = config.js2svg || {};
+    config.js2svg.pretty = true;
+    if (opts.indent != null) {
+      config.js2svg.indent = opts.indent;
+    }
+  }
+
+  // --eol
+  if (opts.eol) {
+    config.js2svg = config.js2svg || {};
+    config.js2svg.eol = opts.eol;
+  }
+
+  // --final-newline
+  if (opts.finalNewline) {
+    config.js2svg = config.js2svg || {};
+    config.js2svg.finalNewline = true;
+  }
+
+  // --output
+  if (output) {
+    if (input.length && input[0] != '-') {
+      if (output.length == 1 && checkIsDir(output[0])) {
+        var dir = output[0];
+        for (var i = 0; i < input.length; i++) {
+          output[i] = checkIsDir(input[i])
+            ? input[i]
+            : path.resolve(dir, path.basename(input[i]));
+        }
+      } else if (output.length < input.length) {
+        output = output.concat(input.slice(output.length));
+      }
+    }
+  } else if (input.length) {
+    output = input;
+  } else if (opts.string) {
+    output = '-';
+  }
+
+  if (opts.datauri) {
+    config.datauri = opts.datauri;
+  }
+
+  // --folder
+  if (opts.folder) {
+    var ouputFolder = (output && output[0]) || opts.folder;
+    await optimizeFolder(config, opts.folder, ouputFolder);
+  }
+
+  // --input
+  if (input.length !== 0) {
+    // STDIN
+    if (input[0] === '-') {
+      return new Promise((resolve, reject) => {
+        var data = '',
+          file = output[0];
+
+        process.stdin
+          .on('data', (chunk) => (data += chunk))
+          .once('end', () =>
+            processSVGData(config, null, data, file).then(resolve, reject),
+          );
+      });
+      // file
+    } else {
+      await Promise.all(
+        input.map((file, n) => optimizeFile(config, file, output[n])),
+      );
+    }
+
+    // --string
+  } else if (opts.string) {
+    var data = decodeSVGDatauri(opts.string);
+
+    return processSVGData(config, null, data, output[0]);
+  }
+}
+
+/**
+ * Optimize SVG files in a directory.
+ *
+ * @param {Object} config options
+ * @param {string} dir input directory
+ * @param {string} output output directory
+ * @return {Promise}
+ */
+function optimizeFolder(config, dir, output) {
+  if (!config.quiet) {
+    console.log(`Processing directory '${dir}':\n`);
+  }
+  return fs.promises
+    .readdir(dir)
+    .then((files) => processDirectory(config, dir, files, output));
+}
+
+/**
+ * Process given files, take only SVG.
+ *
+ * @param {Object} config options
+ * @param {string} dir input directory
+ * @param {Array} files list of file names in the directory
+ * @param {string} output output directory
+ * @return {Promise}
+ */
+function processDirectory(config, dir, files, output) {
+  // take only *.svg files, recursively if necessary
+  var svgFilesDescriptions = getFilesDescriptions(config, dir, files, output);
+
+  return svgFilesDescriptions.length
+    ? Promise.all(
+        svgFilesDescriptions.map((fileDescription) =>
+          optimizeFile(
+            config,
+            fileDescription.inputPath,
+            fileDescription.outputPath,
+          ),
+        ),
+      )
+    : Promise.reject(
+        new Error(`No SVG files have been found in '${dir}' directory.`),
+      );
+}
+
+/**
+ * Get SVG files descriptions.
+ *
+ * @param {Object} config options
+ * @param {string} dir input directory
+ * @param {Array} files list of file names in the directory
+ * @param {string} output output directory
+ * @return {Array}
+ */
+function getFilesDescriptions(config, dir, files, output) {
+  const filesInThisFolder = files
+    .filter(
+      (name) =>
+        regSVGFile.test(name) &&
+        !config.exclude.some((regExclude) => regExclude.test(name)),
+    )
+    .map((name) => ({
+      inputPath: path.resolve(dir, name),
+      outputPath: path.resolve(output, name),
+    }));
+
+  return config.recursive
+    ? [].concat(
+        filesInThisFolder,
+        files
+          .filter((name) => checkIsDir(path.resolve(dir, name)))
+          .map((subFolderName) => {
+            const subFolderPath = path.resolve(dir, subFolderName);
+            const subFolderFiles = fs.readdirSync(subFolderPath);
+            const subFolderOutput = path.resolve(output, subFolderName);
+            return getFilesDescriptions(
+              config,
+              subFolderPath,
+              subFolderFiles,
+              subFolderOutput,
+            );
+          })
+          .reduce((a, b) => [].concat(a, b), []),
+      )
+    : filesInThisFolder;
+}
+
+/**
+ * Read SVG file and pass to processing.
+ *
+ * @param {Object} config options
+ * @param {string} file
+ * @param {string} output
+ * @return {Promise}
+ */
+function optimizeFile(config, file, output) {
+  return fs.promises.readFile(file, 'utf8').then(
+    (data) => processSVGData(config, { path: file }, data, output, file),
+    (error) => checkOptimizeFileError(config, file, output, error),
+  );
+}
+
+/**
+ * Optimize SVG data.
+ *
+ * @param {Object} config options
+ * @param {string} data SVG content to optimize
+ * @param {string} output where to write optimized file
+ * @param {string} [input] input file name (being used if output is a directory)
+ * @return {Promise}
+ */
+function processSVGData(config, info, data, output, input) {
+  var startTime = Date.now(),
+    prevFileSize = Buffer.byteLength(data, 'utf8');
+
+  let result;
+  try {
+    result = optimize(data, { ...config, ...info });
+  } catch (error) {
+    if (error.name === 'SvgoParserError') {
+      console.error(colors.red(error.toString()));
+      process.exit(1);
+    } else {
+      throw error;
+    }
+  }
+  if (config.datauri) {
+    result.data = encodeSVGDatauri(result.data, config.datauri);
+  }
+  var resultFileSize = Buffer.byteLength(result.data, 'utf8'),
+    processingTime = Date.now() - startTime;
+
+  return writeOutput(input, output, result.data).then(
+    function () {
+      if (!config.quiet && output != '-') {
+        if (input) {
+          console.log(`\n${path.basename(input)}:`);
+        }
+        printTimeInfo(processingTime);
+        printProfitInfo(prevFileSize, resultFileSize);
+      }
+    },
+    (error) =>
+      Promise.reject(
+        new Error(
+          error.code === 'ENOTDIR'
+            ? `Error: output '${output}' is not a directory.`
+            : error,
+        ),
+      ),
+  );
+}
+
+/**
+ * Write result of an optimization.
+ *
+ * @param {string} input
+ * @param {string} output output file name. '-' for stdout
+ * @param {string} data data to write
+ * @return {Promise}
+ */
+function writeOutput(input, output, data) {
+  if (output == '-') {
+    process.stdout.write(data);
+    return Promise.resolve();
+  }
+
+  fs.mkdirSync(path.dirname(output), { recursive: true });
+
+  return fs.promises
+    .writeFile(output, data, 'utf8')
+    .catch((error) => checkWriteFileError(input, output, data, error));
+}
+
+/**
+ * Write time taken to optimize.
+ *
+ * @param {number} time time in milliseconds.
+ */
+function printTimeInfo(time) {
+  console.log(`Done in ${time} ms!`);
+}
+
+/**
+ * Write optimizing stats in a human-readable format.
+ *
+ * @param {number} inBytes size before optimization.
+ * @param {number} outBytes size after optimization.
+ */
+function printProfitInfo(inBytes, outBytes) {
+  const profitPercent = 100 - (outBytes * 100) / inBytes;
+  /** @type {[string, Function]} */
+  const ui = profitPercent < 0 ? ['+', colors.red] : ['-', colors.green];
+
+  console.log(
+    Math.round((inBytes / 1024) * 1000) / 1000 + ' KiB',
+    ui[0],
+    ui[1](Math.abs(Math.round(profitPercent * 10) / 10) + '%'),
+    '=',
+    Math.round((outBytes / 1024) * 1000) / 1000 + ' KiB',
+  );
+}
+
+/**
+ * Check for errors, if it's a dir optimize the dir.
+ *
+ * @param {Object} config
+ * @param {string} input
+ * @param {string} output
+ * @param {Error} error
+ * @return {Promise}
+ */
+function checkOptimizeFileError(config, input, output, error) {
+  if (error.code == 'EISDIR') {
+    return optimizeFolder(config, input, output);
+  } else if (error.code == 'ENOENT') {
+    return Promise.reject(
+      new Error(`Error: no such file or directory '${error.path}'.`),
+    );
+  }
+  return Promise.reject(error);
+}
+
+/**
+ * Check for saving file error. If the output is a dir, then write file there.
+ *
+ * @param {string} input
+ * @param {string} output
+ * @param {string} data
+ * @param {Error} error
+ * @return {Promise}
+ */
+function checkWriteFileError(input, output, data, error) {
+  if (error.code == 'EISDIR' && input) {
+    return fs.promises.writeFile(
+      path.resolve(output, path.basename(input)),
+      data,
+      'utf8',
+    );
+  } else {
+    return Promise.reject(error);
+  }
+}
+
+/** Show list of available plugins with short description. */
+function showAvailablePlugins() {
+  const list = builtin
+    .sort((a, b) => a.name.localeCompare(b.name))
+    .map((plugin) => ` [ ${colors.green(plugin.name)} ] ${plugin.description}`)
+    .join('\n');
+  console.log('Currently available plugins:\n' + list);
+}
+
+module.exports.checkIsDir = checkIsDir;

backend/node_modules/svgo/lib/svgo/css-select-adapter.d.ts

@@ -0,0 +1,2 @@
+declare let obj: any;
+export = obj;

backend/node_modules/svgo/lib/svgo/css-select-adapter.js

@@ -0,0 +1,120 @@
+'use strict';
+
+const isTag = (node) => {
+  return node.type === 'element';
+};
+
+const existsOne = (test, elems) => {
+  return elems.some((elem) => {
+    if (isTag(elem)) {
+      return test(elem) || existsOne(test, getChildren(elem));
+    } else {
+      return false;
+    }
+  });
+};
+
+const getAttributeValue = (elem, name) => {
+  return elem.attributes[name];
+};
+
+const getChildren = (node) => {
+  return node.children || [];
+};
+
+const getName = (elemAst) => {
+  return elemAst.name;
+};
+
+const getParent = (node) => {
+  return node.parentNode || null;
+};
+
+const getSiblings = (elem) => {
+  var parent = getParent(elem);
+  return parent ? getChildren(parent) : [];
+};
+
+const getText = (node) => {
+  if (node.children[0].type === 'text' && node.children[0].type === 'cdata') {
+    return node.children[0].value;
+  }
+  return '';
+};
+
+const hasAttrib = (elem, name) => {
+  return elem.attributes[name] !== undefined;
+};
+
+const removeSubsets = (nodes) => {
+  let idx = nodes.length;
+  let node;
+  let ancestor;
+  let replace;
+  // Check if each node (or one of its ancestors) is already contained in the
+  // array.
+  while (--idx > -1) {
+    node = ancestor = nodes[idx];
+    // Temporarily remove the node under consideration
+    nodes[idx] = null;
+    replace = true;
+    while (ancestor) {
+      if (nodes.includes(ancestor)) {
+        replace = false;
+        nodes.splice(idx, 1);
+        break;
+      }
+      ancestor = getParent(ancestor);
+    }
+    // If the node has been found to be unique, re-insert it.
+    if (replace) {
+      nodes[idx] = node;
+    }
+  }
+  return nodes;
+};
+
+const findAll = (test, elems) => {
+  const result = [];
+  for (const elem of elems) {
+    if (isTag(elem)) {
+      if (test(elem)) {
+        result.push(elem);
+      }
+      result.push(...findAll(test, getChildren(elem)));
+    }
+  }
+  return result;
+};
+
+const findOne = (test, elems) => {
+  for (const elem of elems) {
+    if (isTag(elem)) {
+      if (test(elem)) {
+        return elem;
+      }
+      const result = findOne(test, getChildren(elem));
+      if (result) {
+        return result;
+      }
+    }
+  }
+  return null;
+};
+
+const svgoCssSelectAdapter = {
+  isTag,
+  existsOne,
+  getAttributeValue,
+  getChildren,
+  getName,
+  getParent,
+  getSiblings,
+  getText,
+  hasAttrib,
+  removeSubsets,
+  findAll,
+  findOne,
+};
+
+module.exports = svgoCssSelectAdapter;

backend/node_modules/svgo/lib/svgo/plugins.js

@@ -0,0 +1,61 @@
+'use strict';
+
+const { visit } = require('../xast.js');
+
+/**
+ * Plugins engine.
+ *
+ * @module plugins
+ *
+ * @param {Object} ast input ast
+ * @param {Object} info extra information
+ * @param {Array} plugins plugins object from config
+ * @return {Object} output ast
+ */
+const invokePlugins = (ast, info, plugins, overrides, globalOverrides) => {
+  for (const plugin of plugins) {
+    const override = overrides?.[plugin.name];
+    if (override === false) {
+      continue;
+    }
+    const params = { ...plugin.params, ...globalOverrides, ...override };
+
+    const visitor = plugin.fn(ast, params, info);
+    if (visitor != null) {
+      visit(ast, visitor);
+    }
+  }
+};
+exports.invokePlugins = invokePlugins;
+
+const createPreset = ({ name, plugins }) => {
+  return {
+    name,
+    fn: (ast, params, info) => {
+      const { floatPrecision, overrides } = params;
+      const globalOverrides = {};
+      if (floatPrecision != null) {
+        globalOverrides.floatPrecision = floatPrecision;
+      }
+      if (overrides) {
+        const pluginNames = plugins.map(({ name }) => name);
+        for (const pluginName of Object.keys(overrides)) {
+          if (!pluginNames.includes(pluginName)) {
+            console.warn(
+              `You are trying to configure ${pluginName} which is not part of ${name}.\n` +
+                `Try to put it before or after, for example\n\n` +
+                `plugins: [\n` +
+                `  {\n` +
+                `    name: '${name}',\n` +
+                `  },\n` +
+                `  '${pluginName}'\n` +
+                `]\n`,
+            );
+          }
+        }
+      }
+      invokePlugins(ast, info, plugins, overrides, globalOverrides);
+    },
+  };
+};
+exports.createPreset = createPreset;

backend/node_modules/svgo/lib/svgo/tools.js

@@ -0,0 +1,245 @@
+'use strict';
+
+/**
+ * @typedef {import('../../lib/types').XastElement} XastElement
+ * @typedef {import('../types').PathDataCommand} PathDataCommand
+ * @typedef {import('../types').DataUri} DataUri
+ */
+
+const { attrsGroups, referencesProps } = require('../../plugins/_collections');
+
+const regReferencesUrl = /\burl\((["'])?#(.+?)\1\)/g;
+const regReferencesHref = /^#(.+?)$/;
+const regReferencesBegin = /(\w+)\.[a-zA-Z]/;
+
+/**
+ * Encode plain SVG data string into Data URI string.
+ *
+ * @type {(str: string, type?: DataUri) => string}
+ */
+exports.encodeSVGDatauri = (str, type) => {
+  var prefix = 'data:image/svg+xml';
+  if (!type || type === 'base64') {
+    // base64
+    prefix += ';base64,';
+    str = prefix + Buffer.from(str).toString('base64');
+  } else if (type === 'enc') {
+    // URI encoded
+    str = prefix + ',' + encodeURIComponent(str);
+  } else if (type === 'unenc') {
+    // unencoded
+    str = prefix + ',' + str;
+  }
+  return str;
+};
+
+/**
+ * Decode SVG Data URI string into plain SVG string.
+ *
+ * @type {(str: string) => string}
+ */
+exports.decodeSVGDatauri = (str) => {
+  var regexp = /data:image\/svg\+xml(;charset=[^;,]*)?(;base64)?,(.*)/;
+  var match = regexp.exec(str);
+
+  // plain string
+  if (!match) return str;
+
+  var data = match[3];
+
+  if (match[2]) {
+    // base64
+    str = Buffer.from(data, 'base64').toString('utf8');
+  } else if (data.charAt(0) === '%') {
+    // URI encoded
+    str = decodeURIComponent(data);
+  } else if (data.charAt(0) === '<') {
+    // unencoded
+    str = data;
+  }
+  return str;
+};
+
+/**
+ * @typedef {{
+ *   noSpaceAfterFlags?: boolean,
+ *   leadingZero?: boolean,
+ *   negativeExtraSpace?: boolean
+ * }} CleanupOutDataParams
+ */
+
+/**
+ * Convert a row of numbers to an optimized string view.
+ *
+ * @example
+ * [0, -1, .5, .5] → "0-1 .5.5"
+ *
+ * @type {(data: number[], params: CleanupOutDataParams, command?: PathDataCommand) => string}
+ */
+exports.cleanupOutData = (data, params, command) => {
+  let str = '';
+  let delimiter;
+  /**
+   * @type {number}
+   */
+  let prev;
+
+  data.forEach((item, i) => {
+    // space delimiter by default
+    delimiter = ' ';
+
+    // no extra space in front of first number
+    if (i == 0) delimiter = '';
+
+    // no extra space after 'arcto' command flags(large-arc and sweep flags)
+    // a20 60 45 0 1 30 20 → a20 60 45 0130 20
+    if (params.noSpaceAfterFlags && (command == 'A' || command == 'a')) {
+      var pos = i % 7;
+      if (pos == 4 || pos == 5) delimiter = '';
+    }
+
+    // remove floating-point numbers leading zeros
+    // 0.5 → .5
+    // -0.5 → -.5
+    const itemStr = params.leadingZero
+      ? removeLeadingZero(item)
+      : item.toString();
+
+    // no extra space in front of negative number or
+    // in front of a floating number if a previous number is floating too
+    if (
+      params.negativeExtraSpace &&
+      delimiter != '' &&
+      (item < 0 || (itemStr.charAt(0) === '.' && prev % 1 !== 0))
+    ) {
+      delimiter = '';
+    }
+    // save prev item value
+    prev = item;
+    str += delimiter + itemStr;
+  });
+  return str;
+};
+
+/**
+ * Remove floating-point numbers leading zero.
+ *
+ * @param {number} value
+ * @returns {string}
+ * @example
+ * 0.5 → .5
+ * -0.5 → -.5
+ */
+const removeLeadingZero = (value) => {
+  const strValue = value.toString();
+
+  if (0 < value && value < 1 && strValue.startsWith('0')) {
+    return strValue.slice(1);
+  }
+
+  if (-1 < value && value < 0 && strValue[1] === '0') {
+    return strValue[0] + strValue.slice(2);
+  }
+
+  return strValue;
+};
+exports.removeLeadingZero = removeLeadingZero;
+
+/**
+ * If the current node contains any scripts. This does not check parents or
+ * children of the node, only the properties and attributes of the node itself.
+ *
+ * @param {XastElement} node Current node to check against.
+ * @returns {boolean} If the current node contains scripts.
+ */
+const hasScripts = (node) => {
+  if (node.name === 'script' && node.children.length !== 0) {
+    return true;
+  }
+
+  if (node.name === 'a') {
+    const hasJsLinks = Object.entries(node.attributes).some(
+      ([attrKey, attrValue]) =>
+        (attrKey === 'href' || attrKey.endsWith(':href')) &&
+        attrValue != null &&
+        attrValue.trimStart().startsWith('javascript:'),
+    );
+
+    if (hasJsLinks) {
+      return true;
+    }
+  }
+
+  const eventAttrs = [
+    ...attrsGroups.animationEvent,
+    ...attrsGroups.documentEvent,
+    ...attrsGroups.documentElementEvent,
+    ...attrsGroups.globalEvent,
+    ...attrsGroups.graphicalEvent,
+  ];
+
+  return eventAttrs.some((attr) => node.attributes[attr] != null);
+};
+exports.hasScripts = hasScripts;
+
+/**
+ * For example, a string that contains one or more of following would match and
+ * return true:
+ *
+ * * `url(#gradient001)`
+ * * `url('#gradient001')`
+ *
+ * @param {string} body
+ * @returns {boolean} If the given string includes a URL reference.
+ */
+const includesUrlReference = (body) => {
+  return new RegExp(regReferencesUrl).test(body);
+};
+exports.includesUrlReference = includesUrlReference;
+
+/**
+ * @param {string} attribute
+ * @param {string} value
+ * @returns {string[]}
+ */
+const findReferences = (attribute, value) => {
+  const results = [];
+
+  if (referencesProps.has(attribute)) {
+    const matches = value.matchAll(regReferencesUrl);
+    for (const match of matches) {
+      results.push(match[2]);
+    }
+  }
+
+  if (attribute === 'href' || attribute.endsWith(':href')) {
+    const match = regReferencesHref.exec(value);
+    if (match != null) {
+      results.push(match[1]);
+    }
+  }
+
+  if (attribute === 'begin') {
+    const match = regReferencesBegin.exec(value);
+    if (match != null) {
+      results.push(match[1]);
+    }
+  }
+
+  return results.map((body) => decodeURI(body));
+};
+exports.findReferences = findReferences;
+
+/**
+ * Does the same as {@link Number.toFixed} but without casting
+ * the return value to a string.
+ *
+ * @param {number} num
+ * @param {number} precision
+ * @returns {number}
+ */
+const toFixed = (num, precision) => {
+  const pow = 10 ** precision;
+  return Math.round(num * pow) / pow;
+};
+exports.toFixed = toFixed;

backend/node_modules/svgo/lib/types.d.ts

@@ -0,0 +1,174 @@
+export type XastDoctype = {
+  type: 'doctype';
+  name: string;
+  data: {
+    doctype: string;
+  };
+};
+
+export type XastInstruction = {
+  type: 'instruction';
+  name: string;
+  value: string;
+};
+
+export type XastComment = {
+  type: 'comment';
+  value: string;
+};
+
+export type XastCdata = {
+  type: 'cdata';
+  value: string;
+};
+
+export type XastText = {
+  type: 'text';
+  value: string;
+};
+
+export type XastElement = {
+  type: 'element';
+  name: string;
+  attributes: Record<string, string>;
+  children: XastChild[];
+};
+
+export type XastChild =
+  | XastDoctype
+  | XastInstruction
+  | XastComment
+  | XastCdata
+  | XastText
+  | XastElement;
+
+export type XastRoot = {
+  type: 'root';
+  children: XastChild[];
+};
+
+export type XastParent = XastRoot | XastElement;
+
+export type XastNode = XastRoot | XastChild;
+
+export type StringifyOptions = {
+  doctypeStart?: string;
+  doctypeEnd?: string;
+  procInstStart?: string;
+  procInstEnd?: string;
+  tagOpenStart?: string;
+  tagOpenEnd?: string;
+  tagCloseStart?: string;
+  tagCloseEnd?: string;
+  tagShortStart?: string;
+  tagShortEnd?: string;
+  attrStart?: string;
+  attrEnd?: string;
+  commentStart?: string;
+  commentEnd?: string;
+  cdataStart?: string;
+  cdataEnd?: string;
+  textStart?: string;
+  textEnd?: string;
+  indent?: number | string;
+  regEntities?: RegExp;
+  regValEntities?: RegExp;
+  encodeEntity?: (char: string) => string;
+  pretty?: boolean;
+  useShortTags?: boolean;
+  eol?: 'lf' | 'crlf';
+  finalNewline?: boolean;
+};
+
+type VisitorNode<Node> = {
+  enter?: (node: Node, parentNode: XastParent) => void | symbol;
+  exit?: (node: Node, parentNode: XastParent) => void;
+};
+
+type VisitorRoot = {
+  enter?: (node: XastRoot, parentNode: null) => void;
+  exit?: (node: XastRoot, parentNode: null) => void;
+};
+
+export type Visitor = {
+  doctype?: VisitorNode<XastDoctype>;
+  instruction?: VisitorNode<XastInstruction>;
+  comment?: VisitorNode<XastComment>;
+  cdata?: VisitorNode<XastCdata>;
+  text?: VisitorNode<XastText>;
+  element?: VisitorNode<XastElement>;
+  root?: VisitorRoot;
+};
+
+export type PluginInfo = {
+  path?: string;
+  multipassCount: number;
+};
+
+export type Plugin<Params> = (
+  root: XastRoot,
+  params: Params,
+  info: PluginInfo,
+) => null | Visitor;
+
+export type Specificity = [number, number, number];
+
+export type StylesheetDeclaration = {
+  name: string;
+  value: string;
+  important: boolean;
+};
+
+export type StylesheetRule = {
+  dynamic: boolean;
+  selector: string;
+  specificity: Specificity;
+  declarations: StylesheetDeclaration[];
+};
+
+export type Stylesheet = {
+  rules: StylesheetRule[];
+  parents: Map<XastElement, XastParent>;
+};
+
+type StaticStyle = {
+  type: 'static';
+  inherited: boolean;
+  value: string;
+};
+
+type DynamicStyle = {
+  type: 'dynamic';
+  inherited: boolean;
+};
+
+export type ComputedStyles = Record<string, StaticStyle | DynamicStyle>;
+
+export type PathDataCommand =
+  | 'M'
+  | 'm'
+  | 'Z'
+  | 'z'
+  | 'L'
+  | 'l'
+  | 'H'
+  | 'h'
+  | 'V'
+  | 'v'
+  | 'C'
+  | 'c'
+  | 'S'
+  | 's'
+  | 'Q'
+  | 'q'
+  | 'T'
+  | 't'
+  | 'A'
+  | 'a';
+
+export type PathDataItem = {
+  command: PathDataCommand;
+  args: number[];
+};
+
+export type DataUri = 'base64' | 'enc' | 'unenc';

backend/node_modules/svgo/lib/xast.js

@@ -0,0 +1,87 @@
+'use strict';
+
+/**
+ * @typedef {import('./types').XastNode} XastNode
+ * @typedef {import('./types').XastChild} XastChild
+ * @typedef {import('./types').XastParent} XastParent
+ * @typedef {import('./types').Visitor} Visitor
+ */
+
+const { selectAll, selectOne, is } = require('css-select');
+const xastAdaptor = require('./svgo/css-select-adapter.js');
+
+const cssSelectOptions = {
+  xmlMode: true,
+  adapter: xastAdaptor,
+};
+
+/**
+ * @type {(node: XastNode, selector: string) => XastChild[]}
+ */
+const querySelectorAll = (node, selector) => {
+  return selectAll(selector, node, cssSelectOptions);
+};
+exports.querySelectorAll = querySelectorAll;
+
+/**
+ * @type {(node: XastNode, selector: string) => ?XastChild}
+ */
+const querySelector = (node, selector) => {
+  return selectOne(selector, node, cssSelectOptions);
+};
+exports.querySelector = querySelector;
+
+/**
+ * @type {(node: XastChild, selector: string) => boolean}
+ */
+const matches = (node, selector) => {
+  return is(node, selector, cssSelectOptions);
+};
+exports.matches = matches;
+
+const visitSkip = Symbol();
+exports.visitSkip = visitSkip;
+
+/**
+ * @type {(node: XastNode, visitor: Visitor, parentNode?: any) => void}
+ */
+const visit = (node, visitor, parentNode) => {
+  const callbacks = visitor[node.type];
+  if (callbacks && callbacks.enter) {
+    // @ts-ignore hard to infer
+    const symbol = callbacks.enter(node, parentNode);
+    if (symbol === visitSkip) {
+      return;
+    }
+  }
+  // visit root children
+  if (node.type === 'root') {
+    // copy children array to not loose cursor when children is spliced
+    for (const child of node.children) {
+      visit(child, visitor, node);
+    }
+  }
+  // visit element children if still attached to parent
+  if (node.type === 'element') {
+    if (parentNode.children.includes(node)) {
+      for (const child of node.children) {
+        visit(child, visitor, node);
+      }
+    }
+  }
+  if (callbacks && callbacks.exit) {
+    // @ts-ignore hard to infer
+    callbacks.exit(node, parentNode);
+  }
+};
+exports.visit = visit;
+
+/**
+ * @param {XastChild} node
+ * @param {XastParent} parentNode
+ */
+const detachNodeFromParent = (node, parentNode) => {
+  // avoid splice to not break for loops
+  parentNode.children = parentNode.children.filter((child) => child !== node);
+};
+exports.detachNodeFromParent = detachNodeFromParent;