v6 Phase A: Dashboard & Toolbar

- 'Dein Stack' zeigt echtes Modell (Dateiname) hinter coder/scout/vision.
- Top-News-Karte auf der Uebersicht (neben Stack).
- Toolbar-Update-Badges: /api/updates (OS via apt-Cache + Modell-Upgrades),
  klickbar -> Server bzw. News. compute_upgrades aus cookbook wiederverwendet.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

routers/maintenance.py

@@ -72,6 +72,25 @@ def reboot(req: PwdReq):
         pass
     return {"ok": True, "note": "Reboot getriggert."}
 
+@router.get("/updates")
+def updates():
+    """Ausstehende Updates für die Toolbar: OS-Pakete (apt-Cache) + Modell-Upgrades."""
+    import psutil
+    from routers.cookbook import compute_upgrades
+    os_count = 0
+    try:
+        out = subprocess.run(
+            ["bash", "-c", "apt list --upgradable 2>/dev/null | grep -c upgradable || true"],
+            capture_output=True, text=True, timeout=10)
+        os_count = int((out.stdout or "0").strip() or 0)
+    except Exception:  # noqa: BLE001
+        os_count = 0
+    try:
+        models = len(compute_upgrades(psutil.virtual_memory().total / (1024 ** 3)))
+    except Exception:  # noqa: BLE001
+        models = 0
+    return {"os": os_count, "models": models}
+
 @router.websocket("/logs/{service}")
 async def stream_logs(websocket: WebSocket, service: str):
     await websocket.accept()