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>

frontend/src/lib/types.ts

@@ -263,6 +263,54 @@ export interface MarketRegime {
   computed_at?: string;
 }
 
+// AI/Tech Regime-Change Monitor (standalone, observational)
+export type RegimeBand = 'stable' | 'watch' | 'elevated' | 'breaking';
+
+export interface RegimeSignal {
+  id: string;
+  label: string;
+  sub_score: number | null;
+  weight: number;
+  available: boolean;
+  contribution: number;
+}
+
+export interface RegimeMonitor {
+  available: boolean;
+  reason?: string;
+  date?: string;
+  total_score?: number;
+  band?: RegimeBand;
+  alert_threshold?: number;
+  breakdown?: RegimeSignal[];
+  inputs?: {
+    vix: number | null;
+    hy_oas: number | null;
+    fundamentals_fetched_at: string | null;
+  };
+  trend?: { delta_7: number | null; delta_30: number | null };
+}
+
+export interface RegimeFundamentals {
+  f1_score: number;
+  f3_score: number;
+  locked: boolean;
+  reasoning: string | null;
+  fetched_at: string | null;
+  source: string;
+  capex?: Record<string, string>;
+  good_news_stock_down?: string | null;
+}
+
+export interface RegimeConfig {
+  weights: Record<string, number>;
+  alert_threshold: number;
+  tickers: Record<string, unknown>;
+  leader_weight: number;
+  rs_lookback: number;
+  fundamental_staleness_days: number;
+}
+
 export interface AlertConfig {
   enabled: boolean;
   telegram_chat_id: string;