fix: resolve Electron auto-updater 404 errors

- Update repository URL to correct Gitea location
- Disable auto-updates due to Gitea hosting limitations
- Remove GitHub provider configuration from electron-builder
- Add comprehensive documentation for future update strategies
- Fixes HttpError 404 when checking for GitHub releases

The app was trying to check for updates on GitHub but the repository
is hosted on Gitea. Auto-updates are now disabled with manual
distribution as the current update mechanism.

electron/electron-builder.config.json

@@ -11,9 +11,6 @@
     "capacitor.config.*",
     "app/**/*"
   ],
-  "publish": {
-    "provider": "github"
-  },
   "linux": {
     "target": [
       {