fix CRITICAL: zombie process on tool execution timeout (ToolExecutionSandbox.ts)

The old code used Promise.race between a streamPromise and a timeout. When
timeout won, streamPromise was abandoned but its for-await loop continued
indefinitely (zombie). Then a second concurrent for-await stream was started
on the same command, causing duplicate/interleaved output.

Fix: replaced Promise.race + abandoned promise with explicit AbortController
and a single for-await loop that checks abort signal on each iteration.
Timeout clears the loop properly. Background task still starts on timeout.

Author: patil-shubham-dev

apps/desktop/src/renderer/runtime/tools/ToolExecutionSandbox.ts

@@ -252,22 +252,23 @@ export class ToolExecutionSandbox {
     let backgrounded = false
     let backgroundTaskId: string | null = null
 
-    const streamPromise = (async () => {
+    const abortController = new AbortController()
+    const timeoutId = setTimeout(() => abortController.abort(), ASSISTANT_BLOCKING_BUDGET_MS)
+
+    try {
       for await (const event of this.terminalRuntime.runStream(command, cwd, streamOptions)) {
+        if (abortController.signal.aborted) break
         if (event.type === "OUTPUT_LINE" && event.line) {
           // Already handled via onOutput callback
         }
       }
-    })()
-
-    const result = await Promise.race([
-      streamPromise.then(() => 'COMPLETED' as const),
-      new Promise<'TIMEOUT'>((resolve) =>
-        setTimeout(() => resolve('TIMEOUT'), ASSISTANT_BLOCKING_BUDGET_MS),
-      ),
-    ])
+    } catch {
+      // Stream may throw on abort — ignore
+    } finally {
+      clearTimeout(timeoutId)
+    }
 
-    if (result === 'TIMEOUT') {
+    if (abortController.signal.aborted && !abortController.signal.reason) {
       backgrounded = true
       backgroundTaskId = BackgroundTaskManager.getInstance().spawn(
         `Command: ${command.slice(0, 80)}`,