fix(tui): address virtual row and perf log review notes

Keep transcript row keys stable across capped-history trims and rename React Profiler timestamp fields so JSONL consumers don't confuse absolute timestamps with durations.

ui-tui/src/app/useMainApp.ts

@@ -133,6 +133,7 @@ export function useMainApp(gw: GatewayClient) {
   const historyItemsRef = useRef(historyItems)
   const lastUserMsgRef = useRef(lastUserMsg)
   const msgIdsRef = useRef(new WeakMap<Msg, string>())
+  const msgIdSeqRef = useRef(0)
   const heightCachesRef = useRef(new Map<string, Map<string, number>>())
 
   colsRef.current = cols
@@ -180,7 +181,7 @@ export function useMainApp(gw: GatewayClient) {
       return hit
     }
 
-    const next = messageHeightKey(msg)
+    const next = `${messageHeightKey(msg)}:${++msgIdSeqRef.current}`
 
     msgIdsRef.current.set(msg, next)
 
@@ -188,7 +189,7 @@ export function useMainApp(gw: GatewayClient) {
   }, [])
 
   const virtualRows = useMemo<TranscriptRow[]>(
-    () => historyItems.map((msg, index) => ({ index, key: `${index}:${messageId(msg)}`, msg })),
+    () => historyItems.map((msg, index) => ({ index, key: messageId(msg), msg })),
     [historyItems, messageId]
   )
 

ui-tui/src/lib/perfPane.tsx

@@ -53,11 +53,11 @@ const onRender: ProfilerOnRenderCallback = (id, phase, actualMs, baseMs, startTi
   writeRow({
     actualMs: round2(actualMs),
     baseMs: round2(baseMs),
-    commitMs: round2(commitTime),
+    commitTimeMs: round2(commitTime),
     id,
     phase,
     src: 'react',
-    startMs: round2(startTime),
+    startTimeMs: round2(startTime),
     ts: Date.now()
   })
 }