feat: add auto-update system with release checking, notification UI, and install-type-aware apply

- Abstract ReleaseProvider interface (Gitea impl, swappable for GitHub/GitLab)
- Background UpdateService with periodic checks, debounce, dismissed version persistence
- Install type detection (installer/portable/docker/dev) with platform-aware asset matching
- Download with progress events, silent NSIS reinstall, portable ZIP/tarball swap scripts
- Version badge pulse animation, dismissible banner with icon buttons, Settings > Updates tab
- Single source of truth: pyproject.toml version via importlib.metadata, CI stamps tag with sed
- API: GET/POST status, check, dismiss, apply, GET/PUT settings
- i18n: en, ru, zh (27+ keys each)

.gitea/workflows/release.yml

@@ -247,6 +247,7 @@ jobs:
           REGISTRY="${{ steps.meta.outputs.registry }}"
 
           docker build \
+            --build-arg APP_VERSION="${{ steps.meta.outputs.version }}" \
             --label "org.opencontainers.image.version=${{ steps.meta.outputs.version }}" \
             --label "org.opencontainers.image.revision=${{ gitea.sha }}" \
             -t "$REGISTRY:$TAG" \