Add trade setup outcome tracking and performance stats

Closes the feedback loop on R:R scanner signals:

- Nightly outcome_evaluator job replays unresolved setups against daily
  OHLCV bars: target_hit / stop_hit / ambiguous (same-bar, counted as
  loss) / expired after OUTCOME_EVALUATION_MAX_BARS (default 30)
- Migration 004: evaluated_at + outcome_date on trade_setups
- GET /trades/performance: hit rate, expectancy (avg R), total R with
  breakdowns by direction, recommended action, and confidence bucket
- New Performance page (stat cards, breakdown tables, Evaluate Now,
  methodology disclosure) wired into sidebar and mobile nav
- 17 new unit tests for evaluation logic and stats aggregation

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

app/routers/trades.py

@@ -6,6 +6,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from app.dependencies import get_db, require_access
 from app.schemas.common import APIEnvelope
 from app.schemas.trade_setup import RecommendationSummaryResponse, TradeSetupResponse
+from app.services.outcome_service import get_performance_stats
 from app.services.rr_scanner_service import get_trade_setup_history, get_trade_setups
 
 router = APIRouter(tags=["trades"])
@@ -48,6 +49,20 @@ async def list_trade_setups(
     return APIEnvelope(status="success", data=data)
 
 
+@router.get("/trades/performance", response_model=APIEnvelope)
+async def get_trade_performance(
+    _user=Depends(require_access),
+    db: AsyncSession = Depends(get_db),
+) -> APIEnvelope:
+    """Aggregate outcome statistics over evaluated trade setups.
+
+    Outcomes are written by the nightly outcome_evaluator job (win = target
+    hit first, loss = stop hit first, expired = neither within the window).
+    """
+    stats = await get_performance_stats(db)
+    return APIEnvelope(status="success", data=stats)
+
+
 @router.get("/trades/{symbol}", response_model=APIEnvelope)
 async def get_ticker_trade_setups(
     symbol: str,