fix(worker): make cancellation teardown failure-safe

apps/agent-worker/src/workspace-teardown.ts

@@ -0,0 +1,35 @@
+type TeardownStep = () => unknown;
+
+export const teardownWorkspace = async (steps: {
+  stopHeartbeat: TeardownStep;
+  removeActive: TeardownStep;
+  appendEvent?: TeardownStep;
+  abortAgent?: TeardownStep;
+  markStopped?: TeardownStep;
+  closeAgent?: TeardownStep;
+  stopContainer?: TeardownStep;
+  release: TeardownStep;
+}) => {
+  const errors: unknown[] = [];
+  const call = (step: TeardownStep | undefined) => {
+    if (!step) return Promise.resolve();
+    try {
+      return Promise.resolve(step()).catch((error: unknown) => {
+        errors.push(error);
+      });
+    } catch (error) {
+      errors.push(error);
+      return Promise.resolve();
+    }
+  };
+
+  const immediate = [call(steps.stopHeartbeat), call(steps.removeActive)];
+  await Promise.all(immediate);
+  await call(steps.appendEvent);
+  await call(steps.abortAgent);
+  await call(steps.markStopped);
+  await call(steps.closeAgent);
+  await call(steps.stopContainer);
+  await call(steps.release);
+  return { errors };
+};