refactor: complete rewrite as React+FastAPI dashboard

Replace monolithic Jinja2 template with modern stack:

Backend (FastAPI):
- Modular router/service architecture
- Async PostgreSQL (asyncpg) for news from n8n pipeline
- Live Unraid server stats (2 servers via API)
- Home Assistant, Vikunja tasks, weather (wttr.in)
- WebSocket broadcast for real-time updates (15s)
- TTL cache per endpoint, all config via ENV vars

Frontend (React + Vite + TypeScript):
- Glassmorphism dark theme with Tailwind CSS
- Responsive grid: mobile/tablet/desktop/ultrawide
- Weather cards, hourly forecast, news with category tabs
- Server stats (CPU ring, RAM bar, Docker list)
- Home Assistant controls, task management
- Live clock, WebSocket connection indicator

Infrastructure:
- Multi-stage Dockerfile (node:22-alpine + python:3.11-slim)
- docker-compose with full ENV configuration
- Kaniko CI/CD pipeline for GitLab registry

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

web/postcss.config.js

@@ -0,0 +1,6 @@
+export default {
+  plugins: {
+    tailwindcss: {},
+    autoprefixer: {},
+  },
+};