feat: add standalone AI/Tech regime-change monitor tab

A new /regime tab scoring how far the AI/Tech bull regime has deteriorated
toward a re-rating as a single 0-100 index with per-signal breakdown and a
7/30-day trend. Intentionally decoupled: nothing reads its output to gate or
score trades — the daily-pipeline membership is scheduling only.

- regime_monitor_service: price sub-scores (P1-P6 via Alpaca, like
  market_regime), VIX + HY credit spreads via a small FRED helper, weighted
  aggregation over available signals (missing source -> n/a, dropped from the
  denominator), one snapshot row/day, and a ~90-day history backfill by
  replaying the already-fetched series as-of each past day.
- F1/F3 fundamentals proposed by the configured grounded LLM (reuses
  sentiment_provider_service config resolution), with a manual override + lock.
- regime_snapshots table (migration 011); endpoints on the existing market
  router; admin-editable weights/threshold; standalone /regime page.

Data needs: prices via Alpaca, VIX/credit via FRED (optional key — signals show
n/a without it). No LLM needed for history.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/services/admin_service.py

@@ -519,6 +519,7 @@ VALID_JOB_NAMES = {
     "outcome_evaluator",
     "alerts",
     "market_regime",
+    "regime_monitor",
     "backtest",
     "daily_pipeline",
     "intraday_pipeline",
@@ -534,6 +535,7 @@ JOB_LABELS = {
     "outcome_evaluator": "Outcome Evaluator",
     "alerts": "Alerts Dispatcher",
     "market_regime": "Market Regime",
+    "regime_monitor": "Regime Monitor",
     "backtest": "Backtest",
     "daily_pipeline": "Daily Pipeline",
     "intraday_pipeline": "Intraday Pipeline",
@@ -546,6 +548,7 @@ PIPELINE_MEMBERS = {
     "rr_scanner",
     "outcome_evaluator",
     "market_regime",
+    "regime_monitor",
 }