Replace deleted_files with manifest-based updater cleanup, add release workflow

- Add manifest.json generation script (scripts/generate-manifest.php)
- Add Updater::cleanStaleFiles() that removes files not in manifest
- Add /api/v1/update/clean endpoint with backward compatibility
- Add configurable update_protected_paths in config/invoiceshelf.php
- Update frontend to use clean step instead of delete step
- Add GitHub Actions release workflow triggered on version tags
- Add .github/release.yml for auto-generated changelog categories
- Update Makefile to include manifest generation and scripts directory

Backport from v3.0 (e6452946). Adapted for master's existing structure: master uses one-controller-per-action under app/Http/Controllers/V1/Admin/Update/, so the new endpoint is implemented as a dedicated CleanFilesController matching the existing DeleteFilesController/CopyFilesController/etc. pattern instead of v3.0's unified UpdateController. The legacy /update/delete route and DeleteFilesController are retained for compatibility — only the frontend (resources/scripts/admin/views/settings/UpdateAppSetting.vue) is updated to call /update/clean. Updater service lives at app/Space/Updater.php on master (not yet refactored to app/Services/Update/Updater.php like v3.0).

resources/scripts/admin/views/settings/UpdateAppSetting.vue

@@ -263,8 +263,8 @@ const updateSteps = reactive([
     completed: false,
   },
   {
-    translationKey: 'settings.update_app.deleting_files',
-    stepUrl: '/api/v1/update/delete',
+    translationKey: 'settings.update_app.cleaning_stale_files',
+    stepUrl: '/api/v1/update/clean',
     time: null,
     started: false,
     completed: false,