feat: Instrument Snapshot Dashboard — 5-layer synchronized view for 20 instruments

- 20 instruments configured (equity indices, metals, energy, bonds, FX, stocks, crypto)
  each with custom drivers, regime labels, MA periods, event keywords, ai_context
- InstrumentChart: TradingView lightweight-charts candlesticks + MA lines + Bollinger
  + volume histogram + macro event markers overlaid on price
- InstrumentDashboard: regime detection card (scores + signals), trend indicators
  (RSI gauge, MA slopes, momentum, 52W range), events card (links to Timeline),
  AI narrative via GPT-4o-mini (cached by day)
- Backend: instrument_service (OHLCV fetch, indicators, regime scoring, GPT narrative)
  + /api/instruments router (3 endpoints)
- Route: /instruments/:id with selector dropdown, period buttons (3M/6M/1Y/2Y/5Y)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/main.py

@@ -4,6 +4,7 @@ from routers import market_data, geopolitical, options, backtest, ai, portfolio,
 from routers import pattern_lab as pattern_lab_router
 from routers import specialist_desks as specialist_desks_router
 from routers import timeline as timeline_router
+from routers import instruments as instruments_router
 from routers import logs as logs_router
 from routers import var as var_router
 from routers import reports as reports_router
@@ -123,6 +124,7 @@ app.include_router(institutional_router.router)
 app.include_router(pattern_lab_router.router)
 app.include_router(specialist_desks_router.router)
 app.include_router(timeline_router.router)
+app.include_router(instruments_router.router)
 
 
 @app.get("/")