feat: add Admin Panel with JWT auth, DB settings, and integration management

Complete admin backend with login, where all integrations (weather, news,
Home Assistant, Vikunja, Unraid, MQTT) can be configured via web UI instead
of ENV variables. Two-layer config: ENV seeds DB on first start, then DB
is source of truth. Auto-migration system on startup.

Backend: db.py shared pool, auth.py JWT, settings_service CRUD, seed_service,
admin router (protected), test_connections per integration, config.py rewrite.

Frontend: react-router v6, login page, admin layout with sidebar, 8 settings
pages (General, Weather, News, HA, Vikunja, Unraid, MQTT, ChangePassword),
shared IntegrationForm + TestButton components.

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

server/routers/admin.py

@@ -0,0 +1,186 @@
+"""Admin router — protected CRUD for settings, integrations, and MQTT subscriptions."""
+
+from __future__ import annotations
+
+import logging
+from typing import Any, Dict, List, Optional
+
+from fastapi import APIRouter, Depends, HTTPException
+from pydantic import BaseModel
+
+from server.auth import require_admin
+from server.services import settings_service
+from server.services.test_connections import TEST_FUNCTIONS
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter(
+    prefix="/api/admin",
+    tags=["admin"],
+    dependencies=[Depends(require_admin)],
+)
+
+
+# ---------------------------------------------------------------------------
+# Request/Response Models
+# ---------------------------------------------------------------------------
+
+class SettingsUpdate(BaseModel):
+    settings: Dict[str, Any]
+
+
+class IntegrationUpdate(BaseModel):
+    name: Optional[str] = None
+    config: Optional[Dict[str, Any]] = None
+    enabled: Optional[bool] = None
+    display_order: Optional[int] = None
+
+
+class MqttSubscriptionCreate(BaseModel):
+    topic_pattern: str
+    display_name: str = ""
+    category: str = "other"
+    unit: str = ""
+    widget_type: str = "value"
+    enabled: bool = True
+    display_order: int = 0
+
+
+class MqttSubscriptionUpdate(BaseModel):
+    topic_pattern: Optional[str] = None
+    display_name: Optional[str] = None
+    category: Optional[str] = None
+    unit: Optional[str] = None
+    widget_type: Optional[str] = None
+    enabled: Optional[bool] = None
+    display_order: Optional[int] = None
+
+
+# ---------------------------------------------------------------------------
+# Settings
+# ---------------------------------------------------------------------------
+
+@router.get("/settings")
+async def get_settings() -> Dict[str, Any]:
+    """Return all app settings."""
+    return await settings_service.get_all_settings()
+
+
+@router.put("/settings")
+async def update_settings(body: SettingsUpdate) -> Dict[str, str]:
+    """Bulk update settings."""
+    await settings_service.bulk_set_settings(body.settings)
+    # Reload in-memory settings
+    await _reload_app_settings()
+    return {"status": "ok", "message": f"Updated {len(body.settings)} setting(s)"}
+
+
+# ---------------------------------------------------------------------------
+# Integrations
+# ---------------------------------------------------------------------------
+
+@router.get("/integrations")
+async def list_integrations() -> List[Dict[str, Any]]:
+    """List all integration configs."""
+    return await settings_service.get_integrations()
+
+
+@router.get("/integrations/{type_name}")
+async def get_integration(type_name: str) -> Dict[str, Any]:
+    """Get a single integration config."""
+    result = await settings_service.get_integration(type_name)
+    if result is None:
+        raise HTTPException(status_code=404, detail=f"Integration '{type_name}' not found")
+    return result
+
+
+@router.put("/integrations/{type_name}")
+async def update_integration(type_name: str, body: IntegrationUpdate) -> Dict[str, Any]:
+    """Update an integration config."""
+    existing = await settings_service.get_integration(type_name)
+    if existing is None:
+        raise HTTPException(status_code=404, detail=f"Integration '{type_name}' not found")
+
+    result = await settings_service.upsert_integration(
+        type_name=type_name,
+        name=body.name or existing["name"],
+        config=body.config if body.config is not None else existing["config"],
+        enabled=body.enabled if body.enabled is not None else existing["enabled"],
+        display_order=body.display_order if body.display_order is not None else existing["display_order"],
+    )
+
+    # Reload in-memory settings
+    await _reload_app_settings()
+    return result
+
+
+@router.post("/integrations/{type_name}/test")
+async def test_integration(type_name: str) -> Dict[str, Any]:
+    """Test an integration connection."""
+    integration = await settings_service.get_integration(type_name)
+    if integration is None:
+        raise HTTPException(status_code=404, detail=f"Integration '{type_name}' not found")
+
+    test_fn = TEST_FUNCTIONS.get(type_name)
+    if test_fn is None:
+        return {"success": False, "message": f"No test available for '{type_name}'"}
+
+    return await test_fn(integration["config"])
+
+
+# ---------------------------------------------------------------------------
+# MQTT Subscriptions
+# ---------------------------------------------------------------------------
+
+@router.get("/mqtt/subscriptions")
+async def list_mqtt_subscriptions() -> List[Dict[str, Any]]:
+    """List all MQTT subscriptions."""
+    return await settings_service.get_mqtt_subscriptions()
+
+
+@router.post("/mqtt/subscriptions")
+async def create_mqtt_subscription(body: MqttSubscriptionCreate) -> Dict[str, Any]:
+    """Create a new MQTT subscription."""
+    return await settings_service.create_mqtt_subscription(
+        topic_pattern=body.topic_pattern,
+        display_name=body.display_name,
+        category=body.category,
+        unit=body.unit,
+        widget_type=body.widget_type,
+        enabled=body.enabled,
+        display_order=body.display_order,
+    )
+
+
+@router.put("/mqtt/subscriptions/{sub_id}")
+async def update_mqtt_subscription(sub_id: int, body: MqttSubscriptionUpdate) -> Dict[str, Any]:
+    """Update an MQTT subscription."""
+    fields = body.model_dump(exclude_none=True)
+    if not fields:
+        raise HTTPException(status_code=400, detail="No fields to update")
+    result = await settings_service.update_mqtt_subscription(sub_id, **fields)
+    if result is None:
+        raise HTTPException(status_code=404, detail="Subscription not found")
+    return result
+
+
+@router.delete("/mqtt/subscriptions/{sub_id}")
+async def delete_mqtt_subscription(sub_id: int) -> Dict[str, str]:
+    """Delete an MQTT subscription."""
+    deleted = await settings_service.delete_mqtt_subscription(sub_id)
+    if not deleted:
+        raise HTTPException(status_code=404, detail="Subscription not found")
+    return {"status": "ok", "message": "Subscription deleted"}
+
+
+# ---------------------------------------------------------------------------
+# Internal helpers
+# ---------------------------------------------------------------------------
+
+async def _reload_app_settings() -> None:
+    """Reload the in-memory Settings object from the database."""
+    try:
+        from server.config import reload_settings
+        await reload_settings()
+    except Exception:
+        logger.exception("Failed to reload settings after admin change")