🤖 Block workspace rename during active streaming

Prevents race conditions when renaming while AI stream is active:
- Bash tool processes would have stale cwd references
- System message would contain incorrect workspace path
- Git worktree move could conflict with active file operations

Changes:
- Check isStreaming() before allowing rename
- Return clear error message to user
- Add integration test verifying blocking behavior

Rename succeeds immediately after stream completes.

_Generated with `cmux`_

Author: ammar-agent

src/services/ipcMain.ts

@@ -266,6 +266,12 @@ export class IpcMain {
       IPC_CHANNELS.WORKSPACE_RENAME,
       (_event, workspaceId: string, newName: string) => {
         try {
+          // Block rename during active streaming to prevent race conditions
+          // (bash processes would have stale cwd, system message would be wrong)
+          if (this.aiService.isStreaming(workspaceId)) {
+            return Err("Cannot rename workspace while AI stream is active. Please wait for the stream to complete.");
+          }
+
           // Validate workspace name
           const validation = validateWorkspaceName(newName);
           if (!validation.valid) {

tests/ipcMain/renameWorkspace.test.ts

@@ -434,4 +434,56 @@ describeIntegration("IpcMain rename workspace integration tests", () => {
     },
     30000
   );
+
+  test.concurrent(
+    "should fail to rename if workspace is currently streaming",
+    async () => {
+      const { env, workspaceId, tempGitRepo, branchName, cleanup } = await setupWorkspace("anthropic");
+      try {
+        // Add project and workspace to config via IPC
+        await env.mockIpcRenderer.invoke(IPC_CHANNELS.PROJECT_CREATE, tempGitRepo);
+        const projectsConfig = env.config.loadConfigOrDefault();
+        const projectConfig = projectsConfig.projects.get(tempGitRepo);
+        if (projectConfig) {
+          const workspacePath = env.config.getWorkspacePath(tempGitRepo, branchName);
+          projectConfig.workspaces.push({ 
+            path: workspacePath,
+            id: workspaceId,
+            name: branchName
+          });
+          env.config.saveConfig(projectsConfig);
+        }
+
+        // Start a stream (don't await - we want it running)
+        sendMessageWithModel(
+          env.mockIpcRenderer,
+          workspaceId,
+          "What is 2+2?" // Simple query that should complete quickly
+        );
+
+        // Wait for stream to actually start
+        const collector = createEventCollector(env.sentEvents, workspaceId);
+        await collector.waitForEvent("stream-start", 5000);
+
+        // Attempt to rename while streaming - should fail
+        const newName = "renamed-during-stream";
+        const renameResult = await env.mockIpcRenderer.invoke(
+          IPC_CHANNELS.WORKSPACE_RENAME,
+          workspaceId,
+          newName
+        );
+
+        // Verify rename was blocked due to active stream
+        expect(renameResult.success).toBe(false);
+        expect(renameResult.error).toContain("stream is active");
+
+        // Wait for stream to complete
+        await collector.waitForEvent("stream-end", 10000);
+      } finally {
+        await cleanup();
+      }
+    },
+    20000
+  );
+
 });