fix: finish empty Claude Code runs

src/lib/aiAgentStreamCallbacks.test.ts

@@ -152,6 +152,43 @@ describe('aiAgentStreamCallbacks', () => {
     ])
   })
 
+  it('finishes with a readable empty state when Claude exits without assistant text', () => {
+    const messages = createMessageStore([
+      {
+        id: 'msg-1',
+        userMessage: '/exit',
+        actions: [],
+        isStreaming: true,
+      },
+    ])
+    const status = createStatusStore('thinking')
+
+    const callbacks = createStreamCallbacks({
+      messageId: 'msg-1',
+      vaultPath: '/vault',
+      setMessages: messages.setMessages,
+      setStatus: status.setStatus,
+      abortRef: { current: { aborted: false } },
+      responseAccRef: { current: '' },
+      toolInputMapRef: { current: new Map() },
+      fileCallbacksRef: { current: undefined },
+    })
+
+    callbacks.onDone()
+
+    expect(status.getStatus()).toBe('done')
+    expect(messages.getMessages()).toEqual([
+      {
+        id: 'msg-1',
+        userMessage: '/exit',
+        actions: [],
+        isStreaming: false,
+        reasoningDone: true,
+        response: 'Claude Code finished without returning a reply.',
+      },
+    ])
+  })
+
   it('ignores stream events after the request has been aborted', () => {
     const messages = createMessageStore([
       {

src/lib/aiAgentStreamCallbacks.ts

@@ -20,6 +20,12 @@ export interface StreamMutationContext {
   fileCallbacksRef: MutableRefObject<AgentFileCallbacks | undefined>
 }
 
+const EMPTY_CLAUDE_RESPONSE = 'Claude Code finished without returning a reply.'
+
+function finalResponseText(response: string): string {
+  return response.trim() ? response : EMPTY_CLAUDE_RESPONSE
+}
+
 export function createStreamCallbacks(context: StreamMutationContext) {
   const {
     messageId,
@@ -95,7 +101,7 @@ export function createStreamCallbacks(context: StreamMutationContext) {
       if (abortRef.current.aborted) return
 
       setStatus('done')
-      const finalResponse = responseAccRef.current || undefined
+      const finalResponse = finalResponseText(responseAccRef.current)
       updateMessage(setMessages, messageId, (message) => ({
         ...message,
         isStreaming: false,