- Add playbook_allocation_pct and scenario_confidence parameters to
_determine_order_quantity() with playbook-based sizing taking priority
over volatility-score fallback when provided
- Confidence scaling: confidence/80 multiplier (confidence 96 → 1.2x)
clipped to [POSITION_MIN_ALLOCATION_PCT, POSITION_MAX_ALLOCATION_PCT]
- Pass matched_scenario.allocation_pct and match.confidence from
trading_cycle so AI's allocation decisions reach order execution
- Add 4 new tests: playbook priority, confidence scaling, max clamp,
and fallback behavior
Closes#172
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>