feat: add /api/backrest route

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

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