feat: instrument analysis

frontend/src/App.tsx

@@ -140,8 +140,15 @@ function NormalRoutes() {
   const location = useLocation()
   if (KEEP_ALIVE_PATHS.has(location.pathname)) return null
 
-  // On instrument paths the keep-alive layer renders the UI; this Routes just registers the tab
-  const isInstrument = /^\/instruments\/\w/.test(location.pathname)
+  // On instrument paths the keep-alive layer renders the UI; this Routes just registers the tab.
+  // Was `/^\/instruments\/\w/` (required a word char right after the slash) — encoded ids
+  // that start with a character encodeURIComponent escapes (^GSPC -> %5EGSPC) begin with
+  // "%", which isn't \w, so this evaluated false for that tab. isInstrument then picked
+  // 'flex-1 overflow-auto' instead of 'hidden' for this otherwise-empty div, and — since
+  // InstrumentKeepAlive's own div is ALSO flex-1 in the same flex column — the two split
+  // the available height roughly 50/50 instead of the instrument page getting all of it,
+  // which is exactly the "page only fills half the screen" symptom.
+  const isInstrument = location.pathname.startsWith('/instruments/')
 
   return (
     <div className={isInstrument ? 'hidden' : 'flex-1 overflow-auto'}>

frontend/src/components/layout/TabBar.tsx

@@ -69,7 +69,13 @@ export default function TabBar() {
         {/* Dynamic instrument tabs */}
         {instrumentIds.map(id => {
           const path = `/instruments/${id}`
-          const isActive = activePath.toLowerCase() === path.toLowerCase()
+          // activePath keeps its percent-encoding (EURUSD=X -> /instruments/EURUSD%3DX)
+          // while `id` is already decoded — same mismatch fixed in App.tsx's
+          // InstrumentKeepAlive, needed again here or this tab never lights up as active
+          // for any id containing a character encodeURIComponent escapes ("=").
+          let decodedActivePath = activePath
+          try { decodedActivePath = decodeURIComponent(activePath) } catch { /* malformed sequence, compare as-is */ }
+          const isActive = decodedActivePath.toLowerCase() === path.toLowerCase()
           return (
             <button
               key={id}