Separate JSON API backend + React+react-router frontend

- vm_api.py: pure FastAPI JSON API on :8098, CORS enabled
- vm-api.service: systemd unit for API backend
- frontend/: Vite + React 18 + react-router-dom 7 + TanStack Query
- React pages: messages, contacts, contact history, settings, login, logout
- Apache: /api/ proxy to :8098, DocumentRoot -> frontend/dist, SPA fallback
- Backward compat: old :8099 portal still running as fallback

.gitignore

@@ -33,3 +33,4 @@ venv/
 *.swp
 .DS_Store
 frontend/node_modules/
+frontend/node_modules/