feat: add /api/immich route

apps/dashboard/backend/app/routes/immich.py

@@ -0,0 +1,16 @@
+from __future__ import annotations
+
+from fastapi import APIRouter, Depends
+
+from app.models.sources import ImmichSnapshot
+from app.services.aggregator import AggregatorService, get_aggregator_service
+
+
+router = APIRouter(prefix="/api", tags=["immich"])
+
+
+@router.get("/immich", response_model=ImmichSnapshot)
+async def get_immich(
+    aggregator: AggregatorService = Depends(get_aggregator_service),
+) -> ImmichSnapshot:
+    return await aggregator.get_immich()