Small genai fix (#14850)

* Ensure the regenerate button shows when genai is only enabled at the camera level

* update docs

frigate/api/event.py

@@ -996,9 +996,11 @@ def regenerate_description(
             status_code=404,
         )
 
+    camera_config = request.app.frigate_config.cameras[event.camera]
+
     if (
         request.app.frigate_config.semantic_search.enabled
-        and request.app.frigate_config.genai.enabled
+        and camera_config.genai.enabled
     ):
         request.app.event_metadata_updater.publish((event.id, params.source))