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/postcss-js/async.js

@@ -0,0 +1,15 @@
+let postcss = require('postcss')
+
+let processResult = require('./process-result')
+let parse = require('./parser')
+
+module.exports = function async(plugins) {
+  let processor = postcss(plugins)
+  return async input => {
+    let result = await processor.process(input, {
+      parser: parse,
+      from: undefined
+    })
+    return processResult(result)
+  }
+}