fix(core)#20941: reap orphaned descendant processes on PTY abort (#21124)

Co-authored-by: Spencer <spencertang@google.com>

packages/core/src/services/shellExecutionService.test.ts

@@ -1398,12 +1398,11 @@ describe('ShellExecutionService child_process fallback', () => {
               expectedSignal,
             );
           } else {
-            expect(mockCpSpawn).toHaveBeenCalledWith(expectedCommand, [
-              '/pid',
-              String(mockChildProcess.pid),
-              '/f',
-              '/t',
-            ]);
+            expect(mockCpSpawn).toHaveBeenCalledWith(
+              expectedCommand,
+              ['/pid', String(mockChildProcess.pid), '/f', '/t'],
+              undefined,
+            );
           }
         });
       },

packages/core/src/services/shellExecutionService.ts

@@ -1181,10 +1181,12 @@ export class ShellExecutionService {
     await this.cleanupLogStream(pid);
 
     if (activeChild) {
-      killProcessGroup({ pid }).catch(() => {});
+      await killProcessGroup({ pid }).catch(() => {});
       this.activeChildProcesses.delete(pid);
     } else if (activePty) {
-      killProcessGroup({ pid, pty: activePty.ptyProcess }).catch(() => {});
+      await killProcessGroup({ pid, pty: activePty.ptyProcess }).catch(
+        () => {},
+      );
       try {
         (activePty.ptyProcess as IPty & { destroy?: () => void }).destroy?.();
       } catch {