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/services/admin_service.py

@@ -400,6 +400,7 @@ VALID_JOB_NAMES = {
     "fundamental_collector",
     "rr_scanner",
     "ticker_universe_sync",
+    "outcome_evaluator",
 }
 
 JOB_LABELS = {
@@ -408,6 +409,7 @@ JOB_LABELS = {
     "fundamental_collector": "Fundamental Collector",
     "rr_scanner": "R:R Scanner",
     "ticker_universe_sync": "Ticker Universe Sync",
+    "outcome_evaluator": "Outcome Evaluator",
 }