Add gold_silver_ratio indicator (xyz:GOLD / xyz:SILVER) with fallback
reference of 61.59, mirroring the existing WTI/BRENT ratio setup.
Also register xyz:GOLD and xyz:SILVER in WATCHED_COINS and data_fetcher
defaults so the candle data is fetched for the new indicator.
- Remove ASTER, PUMP, ZEC from WATCHED_COINS in main_app.py
- Remove ASTER, PUMP, ZEC from coin_id_map.json (stops market cap collection)
- Remove ASTER, PUMP, ZEC from market_cap_data.json summary
- Remove ASTER, PUMP, ZEC manual overrides from coin_id_map.py
- Remove ASTER, PUMP, ZEC from resampling_status.json (gitignored)
- Add WIKI/symbol_management.md documentation for adding/removing symbols
Existing data in market_data.db is preserved; only new data collection stops.
