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>

frontend/src/App.tsx

@@ -25,6 +25,8 @@ import InstitutionalReports from './pages/InstitutionalReports'
 import SpecialistDesks from './pages/SpecialistDesks'
 import Timeline from './pages/Timeline'
 import ExternalSnapshot from './pages/ExternalSnapshot'
+import InstrumentDashboard from './pages/InstrumentDashboard'
+import { Navigate } from 'react-router-dom'
 import { useCycleWatcher } from './hooks/useApi'
 
 function GlobalWatcher() {
@@ -65,6 +67,8 @@ export default function App() {
             <Route path="/specialist-desks" element={<SpecialistDesks />} />
             <Route path="/timeline" element={<Timeline />} />
             <Route path="/snapshot" element={<ExternalSnapshot />} />
+            <Route path="/instruments" element={<Navigate to="/instruments/SPY" replace />} />
+            <Route path="/instruments/:id" element={<InstrumentDashboard />} />
           </Routes>
         </main>
       </div>