harden delivery pipeline and production runtime

backend/app.py

@@ -1,4 +1,8 @@
+from collections.abc import AsyncIterator
+from contextlib import asynccontextmanager
+
 from fastapi import FastAPI
+from starlette.datastructures import State
 
 from backend.routes.ml import init_ml_routes
 from app.ml.registry.model_registry import ModelRegistry
@@ -6,14 +10,20 @@ from app.ml.training import TrainingPipeline
 from app.ml.feature_store import FeatureStore, FeatureVector
 
 
-def create_app() -> FastAPI:
-    application = FastAPI(title="SillyHome Next ML")
-    init_ml_routes(application)
+@asynccontextmanager
+async def lifespan(application: FastAPI) -> AsyncIterator[None]:
+    application.state.registry = ModelRegistry(application.state.model_store)
     _seed_default_model(application.state)
+    yield
+
+
+def create_app() -> FastAPI:
+    application = FastAPI(title="SillyHome Next ML", lifespan=lifespan)
+    init_ml_routes(application)
     return application
 
 
-def _seed_default_model(state) -> None:  # noqa: ANN001
+def _seed_default_model(state: State) -> None:
     registry = getattr(state, "registry", None)
     if registry is None:
         registry = ModelRegistry(".model_store")