feat: instrument analysis

frontend/src/App.tsx

@@ -100,7 +100,7 @@ function KeepAlivePage({ path, component: Component }: { path: string; component
 
 // Registers the instrument tab on navigation (renders nothing itself)
 function InstrumentRoute() {
-  const { id = 'EURUSD' } = useParams<{ id: string }>()
+  const { id = localStorage.getItem('last_instrument') || 'EURUSD' } = useParams<{ id: string }>()
   const { openInstrument } = useTabs()
   useEffect(() => { openInstrument(id.toUpperCase()) }, [id, openInstrument])
   return null
@@ -112,7 +112,7 @@ function InstrumentKeepAlive({ id }: { id: string }) {
   const isActive = location.pathname.toLowerCase() === `/instruments/${id.toLowerCase()}`
   return (
     <div className={isActive ? 'flex-1 min-h-0 overflow-y-auto' : 'hidden'}>
-      <InstrumentDashboard instrumentIdProp={id} />
+      <InstrumentDashboard instrumentIdProp={id} isVisible={isActive} />
     </div>
   )
 }
@@ -129,7 +129,7 @@ function NormalRoutes() {
   return (
     <div className={isInstrument ? 'hidden' : 'flex-1 overflow-auto'}>
       <Routes>
-        <Route path="/instruments" element={<Navigate to="/instruments/EURUSD" replace />} />
+        <Route path="/instruments" element={<Navigate to={`/instruments/${localStorage.getItem('last_instrument') || 'EURUSD'}`} replace />} />
         <Route path="/instruments/:id" element={<InstrumentRoute />} />
         {/* Legacy redirects */}
         <Route path="/impact"    element={<Navigate to="/market-events" replace />} />

frontend/src/context/TabsContext.tsx

@@ -28,8 +28,10 @@ export function TabsProvider({ children }: { children: ReactNode }) {
   const forgetRoute = useCallback((r: string) =>
     setKept(p => { const n = new Set(p); n.delete(r); return n }), [])
 
-  const openInstrument = useCallback((id: string) =>
-    setInstrumentIds(p => p.includes(id) ? p : [...p, id]), [])
+  const openInstrument = useCallback((id: string) => {
+    localStorage.setItem('last_instrument', id)
+    setInstrumentIds(p => p.includes(id) ? p : [...p, id])
+  }, [])
 
   const closeInstrument = useCallback((id: string) =>
     setInstrumentIds(p => p.filter(x => x !== id)), [])

frontend/src/pages/InstrumentDashboard.tsx

@@ -1205,8 +1205,8 @@ const PERIODS = [
   { key: '5y',  label: '5Y'  },
 ]
 
-export default function InstrumentDashboard({ instrumentIdProp }: { instrumentIdProp?: string } = {}) {
-  const { id: paramId = 'EURUSD' } = useParams<{ id: string }>()
+export default function InstrumentDashboard({ instrumentIdProp, isVisible }: { instrumentIdProp?: string; isVisible?: boolean } = {}) {
+  const { id: paramId = localStorage.getItem('last_instrument') || 'EURUSD' } = useParams<{ id: string }>()
   const navigate = useNavigate()
   const [period, setPeriod]           = useState('1y')
   const [chartStyle, setChartStyle]   = useState<'candles' | 'line'>('candles')
@@ -1237,6 +1237,14 @@ export default function InstrumentDashboard({ instrumentIdProp }: { instrumentId
     api.get('/causal-lab/templates').then(r => setTemplates(r.data)).catch(() => {})
   }, [])
 
+  // Silent refresh when the tab becomes visible again (e.g. after analysis updated from MarketEvents)
+  const mountedRef = useRef(false)
+  useEffect(() => {
+    if (!mountedRef.current) { mountedRef.current = true; return }
+    if (isVisible) fetchSnapshotSilent()
+  // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [isVisible])
+
   const fetchSnapshot = useCallback(() => {
     setLoading(true)
     api.get(`/instruments/${instrumentId}/snapshot?period=${period}`)