Cache now stores only user metadata and timestamps. Price data is
managed exclusively by IntervalPool (single source of truth).
Changes:
- cache.py: Remove price_data and last_price_update fields
- core.py: Remove _cached_price_data, update references to use Pool
- core.py: Rename _data_fetcher to _price_data_manager
- AGENTS.md: Update class naming examples (DataFetcher → PriceDataManager)
This completes the Pool integration architecture where IntervalPool
handles all price data persistence and coordinator cache handles
only user account metadata.