- Add realized_pnl column to transactions table with alembic migration
- Calculate realized PnL on sell transactions: (sell_price - avg_price) * quantity
- Show total realized/unrealized PnL in portfolio detail summary cards
- Show per-transaction realized PnL in transaction history table
- Add position sizing API endpoint (GET /portfolios/{id}/position-size)
- Show position sizing guide in signal execution modal for buy signals
- 8 new E2E tests, all 88 tests passing
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Generic single-database configuration.