fix(core): prevent race condition crash during shell auto-promotion

packages/core/src/services/shellExecutionService.ts

@@ -1341,6 +1341,11 @@ export class ShellExecutionService {
     const activePty = this.activePtys.get(pid);
     const activeChild = this.activeChildProcesses.get(pid);
 
+    // If the process has already exited, there is no need to background it.
+    if (!activePty && !activeChild) {
+      return;
+    }
+
     const resolvedSessionId =
       sessionId ?? activePty?.sessionId ?? activeChild?.sessionId;
     const resolvedCommand =

packages/core/src/tools/shell.ts

@@ -515,7 +515,13 @@ export class ShellToolInvocation extends BaseToolInvocation<
         if (shouldAutoPromote && currentPid) {
           if (this._autoPromoteTimer) clearTimeout(this._autoPromoteTimer);
           this._autoPromoteTimer = setTimeout(() => {
-            ShellExecutionService.background(currentPid!);
+            const sessionId =
+              this.context.config?.getSessionId?.() ?? 'default';
+            ShellExecutionService.background(
+              currentPid!,
+              sessionId,
+              strippedCommand,
+            );
           }, waitMs);
         }
       };