Replace the legacy desktop/Tkinter client and packaging artifacts with a Docker-first, web-hosted approach.
- Add Docker quickstart and run-from-source instructions to the README to simplify deployment.
- Simplify launcher to invoke the new web backend module instead of the old desktop entrypoint.
- Update dependencies for a web UI stack (FastAPI, Uvicorn, python-socketio, Jinja2, etc.) and remove desktop/tray-specific packages.
- Remove legacy GUI, packaging and platform-specific helper code, along with obsolete build/pack scripts and AppImage assets to declutter the repo.
- Tidy project ignore rules to add runtime logs and editor metadata.
Rationale: streamline deployment, favor a browser-accessible interface, and reduce maintenance overhead from multiple platform-specific GUI/packaging implementations.
