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>

server/routers/tasks.py

@@ -0,0 +1,47 @@
+"""Vikunja tasks router."""
+
+from __future__ import annotations
+
+import logging
+from typing import Any, Dict
+
+from fastapi import APIRouter
+
+from server.cache import cache
+from server.config import settings
+from server.services.vikunja_service import fetch_tasks
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter(prefix="/api", tags=["tasks"])
+
+CACHE_KEY = "tasks"
+
+
+@router.get("/tasks")
+async def get_tasks() -> Dict[str, Any]:
+    """Return Vikunja task data.
+
+    The exact shape depends on what ``fetch_tasks`` returns; on failure an
+    error stub is returned instead::
+
+        { "error": true, "message": "..." }
+    """
+
+    # --- cache hit? -----------------------------------------------------------
+    cached = await cache.get(CACHE_KEY)
+    if cached is not None:
+        return cached
+
+    # --- cache miss -----------------------------------------------------------
+    try:
+        data: Dict[str, Any] = await fetch_tasks(
+            settings.vikunja_url,
+            settings.vikunja_token,
+        )
+    except Exception as exc:
+        logger.exception("Failed to fetch Vikunja tasks")
+        return {"error": True, "message": str(exc)}
+
+    await cache.set(CACHE_KEY, data, settings.vikunja_cache_ttl)
+    return data