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/README.md

@@ -0,0 +1,22 @@
+# PostCSS JS
+
+<img align="right" width="135" height="95"
+     title="Philosopher’s stone, logo of PostCSS"
+     src="https://postcss.org/logo-leftp.svg">
+
+[PostCSS] for CSS-in-JS and styles in JS objects.
+
+For example, to use [Stylelint] or [RTLCSS] plugins in your workflow.
+
+<a href="https://evilmartians.com/?utm_source=postcss-js">
+  <img src="https://evilmartians.com/badges/sponsored-by-evil-martians.svg"
+       alt="Sponsored by Evil Martians" width="236" height="54">
+</a>
+
+[Stylelint]: https://github.com/stylelint/stylelint
+[PostCSS]:   https://github.com/postcss/postcss
+[RTLCSS]:    https://github.com/MohammadYounes/rtlcss
+
+
+## Docs
+Read full docs **[here](https://github.com/postcss/postcss-js#readme)**.