fix: resolve lifecycle memory leaks by cleaning up listeners and root closures (#25049)

packages/core/src/services/shellExecutionService.ts

@@ -704,7 +704,10 @@ export class ShellExecutionService {
 
         const finalStrippedOutput = stripAnsi(combinedOutput).trim();
         const exitCode = code;
-        const exitSignal = signal ? os.constants.signals[signal] : null;
+        const exitSignal =
+          signal && os.constants.signals
+            ? (os.constants.signals[signal] ?? null)
+            : null;
 
         const resultPayload: ShellExecutionResult = {
           rawOutput: Buffer.from(''),
@@ -1503,4 +1506,16 @@ export class ShellExecutionService {
       signal: info.signal,
     }));
   }
+
+  /**
+   * Resets the internal state of the ShellExecutionService.
+   * This is intended for use in tests to ensure isolation.
+   */
+  static resetForTest(): void {
+    this.activePtys.clear();
+    this.activeChildProcesses.clear();
+    this.backgroundLogPids.clear();
+    this.backgroundLogStreams.clear();
+    this.backgroundProcessHistory.clear();
+  }
 }