Rename and refactor data_fetching.py → price_data_manager.py to reflect
actual responsibilities:
- User data: Fetches directly via API, validates, caches
- Price data: Delegates to IntervalPool (single source of truth)
Key changes:
- Add should_fetch_tomorrow_data() for intelligent API call decisions
- Add include_tomorrow parameter to prevent API spam before 13:00
- Remove cached_price_data property (Pool is source of truth)
- Update tests to use new class name
Impact: Clearer separation of concerns, reduced API calls through
intelligent tomorrow data fetching logic.