Add proper loading and empty states

- Description: The app uses simple loading text instead of structured states.
- Acceptance Criteria:
- Add loading states for profile, pool, and match data.
- Add empty states for “no profile yet” and “not in pool”.
- Keep the UI style consistent.
- Proof: attach a screenshot of the loading or empty state.

Start by locating the profile, pool, and match data views and reading how each currently displays simple loading text. Add consistent loading and empty states for the listed conditions, then verify the acceptance criteria and attach a screenshot showing one of the new states.

Written by the indexing model from the issue text.