Implement FastAPI Temporal MVP pipeline

app/api/routers/health.py

@@ -0,0 +1,13 @@
+"""Health check routes."""
+
+from fastapi import APIRouter
+
+router = APIRouter(tags=["health"])
+
+
+@router.get("/healthz")
+async def healthcheck() -> dict[str, str]:
+    """Return a simple health check response."""
+
+    return {"status": "ok"}
+