reflex run --frontend-only should support hot reload
Describe the bug
When running reflex run --frontend-only (this is dev mode), hot reload only works for changes made to assets/ folder. We should make it work in general - i.e. if page definitions change (from python files), recompile should occur and dev site updated on the fly.
To Reproduce
reflex run --frontend-only, change something in the application (python code). Running dev server will not pick up this change.
Expected behavior
Running dev server should pick up this change. An obvious bar is to matchreflex run behavior (dev mode, backend and frontend up).
There should be a warning in the docs on reflex run --frontend-only that hot reload won't work this way
Hot reload is actually handled by the backend (feature of granian/uvicorn).
This code explicitly skips front end compilation when --backend-only is passed:
https://github.com/reflex-dev/reflex/blob/fb19fb42968c4ee6ffa12245736724995c8c2243/reflex/reflex.py#L161-L162