Move runtime application state into a dedicated runtime state manager

backend/app/utils/setup_state.py

@@ -2,17 +2,22 @@
 
 from __future__ import annotations
 
-from fastapi import FastAPI
+from typing import TYPE_CHECKING
+
+from app.utils.runtime_state import get_runtime_state
+
+if TYPE_CHECKING:  # pragma: no cover
+    from fastapi import FastAPI
 
 
 def is_setup_complete_cached(app: FastAPI) -> bool:
-    """Return the cached setup completion state from application state."""
-    return getattr(app.state, "setup_complete_cached", False)
+    """Return the cached setup completion state from the runtime state manager."""
+    return get_runtime_state(app).setup_complete_cached
 
 
 def set_setup_complete_cache(app: FastAPI, completed: bool) -> None:
-    """Set the cached setup completion state on application state."""
-    app.state.setup_complete_cached = completed
+    """Set the cached setup completion state on the runtime state manager."""
+    get_runtime_state(app).setup_complete_cached = completed
 
 
 def invalidate_setup_complete_cache(app: FastAPI) -> None:
@@ -21,4 +26,4 @@ def invalidate_setup_complete_cache(app: FastAPI) -> None:
     This helper exists so the cache can be invalidated explicitly if the
     application state changes during runtime.
     """
-    app.state.setup_complete_cached = False
+    get_runtime_state(app).setup_complete_cached = False