Adds a daily_pnl SQLite table that accumulates trade history indefinitely.
On each hourly fetch, fresh API data is upserted (not replaced) so entries
older than Tradovate's 28-day limit are preserved. Cache is loaded at startup
and used as fallback when both report requests fail.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
