feat: add system health diagnostics

backend/app/system_health/router.py

@@ -0,0 +1,27 @@
+"""HTTP boundary for the System Health overview."""
+
+from typing import Annotated
+
+from fastapi import APIRouter, Depends, Response
+
+from app.identity import require_permission
+from app.system_health.dependencies import get_system_health_service
+from app.system_health.models import SystemHealthOverviewResponse
+from app.system_health.service import SystemHealthService
+
+
+router = APIRouter(prefix="/api/system", tags=["system-health"])
+SystemHealthUser = Annotated[dict, Depends(require_permission("system_health.view"))]
+SystemHealthServiceDependency = Annotated[
+    SystemHealthService, Depends(get_system_health_service)
+]
+
+
+@router.get("/health-summary", response_model=SystemHealthOverviewResponse)
+def get_system_health_overview(
+    current_user: SystemHealthUser,
+    service: SystemHealthServiceDependency,
+    response: Response,
+) -> SystemHealthOverviewResponse:
+    response.headers["Cache-Control"] = "no-store"
+    return service.get_overview()