## CHANGES

- Smoothed tab switching by resizing textarea only when active tab changes 🚀
- Reduced costly layout reflows by dropping per-keystroke resize dependencies ⚡
- Prevented agent-config undefined states during slow SSH detection with fallbacks 🛡️
- Added placeholder agent configs from tiles to handle detection race conditions 🧩

src/renderer/components/InputArea.tsx

@@ -282,14 +282,16 @@ export const InputArea = React.memo(function InputArea(props: InputAreaProps) {
       .slice(0, 10);
   }, [currentCommandHistory, commandHistoryFilterLower]);
 
-  // Auto-resize textarea when inputValue changes externally (e.g., tab switch)
+  // Auto-resize textarea when switching tabs
   // This ensures the textarea height matches the content when switching between tabs
+  // PERF: Only depend on activeTabId, NOT inputValue - inputValue changes on every keystroke
+  // and would cause expensive layout reflow (scrollHeight access) on each character typed
   useEffect(() => {
     if (inputRef.current) {
       inputRef.current.style.height = 'auto';
       inputRef.current.style.height = `${Math.min(inputRef.current.scrollHeight, 112)}px`;
     }
-  }, [inputValue, inputRef]);
+  }, [session.activeTabId, inputRef]);
 
   // Show summarization progress overlay when active for this tab
   if (isSummarizing && session.inputMode === 'ai' && onCancelSummarize) {

src/renderer/components/Wizard/screens/AgentSelectionScreen.tsx

@@ -750,8 +750,23 @@ export function AgentSelectionScreen({ theme }: AgentSelectionScreenProps): JSX.
   }, [configuringAgentId]);
 
   // Get the agent being configured
-  const configuringAgent = detectedAgents.find(a => a.id === configuringAgentId);
+  // When SSH detection is in progress, detectedAgents may be stale or empty.
+  // Create a fallback agent config from AGENT_TILES to prevent undefined state.
   const configuringTile = AGENT_TILES.find(t => t.id === configuringAgentId);
+  const detectedConfigAgent = detectedAgents.find(a => a.id === configuringAgentId);
+
+  // If agent not in detectedAgents but we have a tile, create a placeholder
+  // This handles the race condition when SSH detection is slow/pending
+  const configuringAgent: AgentConfig | undefined = detectedConfigAgent ?? (
+    configuringAgentId && configuringTile ? {
+      id: configuringAgentId,
+      name: configuringTile.name,
+      available: false, // Will be updated when detection completes
+      path: undefined,
+      hidden: false,
+      capabilities: undefined, // Will be populated when detection completes
+    } : undefined
+  );
 
   // Loading state
   if (isDetecting) {