feat: Major updates to backend structure and security enhancements

- Removed `COMMON_ERRORS.md` file to streamline documentation.
- Added `Flask-Limiter` for rate limiting and `redis` for session management in `requirements.txt`.
- Expanded `ROADMAP.md` to include completed security features and planned enhancements for version 2.2.
- Enhanced `setup_myp.sh` for ultra-secure kiosk installation, including system hardening and security configurations.
- Updated `app.py` to integrate CSRF protection and improved logging setup.
- Refactored user model to include username and active status for better user management.
- Improved job scheduler with uptime tracking and task management features.
- Updated various templates for a more cohesive user interface and experience.

backend/app/node_modules/reusify/reusify.js

@@ -0,0 +1,33 @@
+'use strict'
+
+function reusify (Constructor) {
+  var head = new Constructor()
+  var tail = head
+
+  function get () {
+    var current = head
+
+    if (current.next) {
+      head = current.next
+    } else {
+      head = new Constructor()
+      tail = head
+    }
+
+    current.next = null
+
+    return current
+  }
+
+  function release (obj) {
+    tail.next = obj
+    tail = obj
+  }
+
+  return {
+    get: get,
+    release: release
+  }
+}
+
+module.exports = reusify