fix(pi): settle delayed compact ownership

tests/unit/pi-background-lifecycle.test.ts

@@ -36,6 +36,8 @@ class LifecycleFakeWorker implements PiConversationWorker {
   private readonly events = new Set<(event: PiRpcEvent) => void>();
   private readonly invalidations = new Set<(error: PiProcessError) => void>();
   private timeoutType: string | null = null;
+  private deferredType: string | null = null;
+  private deferredReject: ((error: unknown) => void) | null = null;
   private compacted = false;
   private lateResult: PiRpcRequestOptions['onLateResult'];
 
@@ -57,6 +59,12 @@ class LifecycleFakeWorker implements PiConversationWorker {
         )), 10_000);
       });
     }
+    if (this.deferredType === command.type) {
+      this.deferredType = null;
+      await new Promise<void>((_resolve, reject) => {
+        this.deferredReject = reject;
+      });
+    }
     const data = command.type === 'get_state'
       ? {
           sessionId: `session-${this.id}`,
@@ -132,6 +140,15 @@ class LifecycleFakeWorker implements PiConversationWorker {
     this.timeoutType = type;
   }
 
+  deferNext(type: string): void {
+    this.deferredType = type;
+  }
+
+  rejectDeferred(error: unknown): void {
+    this.deferredReject?.(error);
+    this.deferredReject = null;
+  }
+
   completeLateSuccess(): void {
     this.lateResult?.({
       response: { type: 'response', id: 'late-proof', success: true },
@@ -354,7 +371,7 @@ describe('Pi run background lifecycle lease', () => {
       willRetry: false,
     });
     expect((await runtime.getSnapshot(runningConversation.id)).context.compaction).toBe('idle');
-    workersByConversation.get(runningConversation.id)!.emit({ type: 'agent_settled' });
+    workersByConversation.get(runningConversation.id)!.completeLateSuccess();
     await expect.poll(async () => (
       await runtime.getSnapshot(runningConversation.id)
     ).run.status).toBe('idle');
@@ -363,6 +380,31 @@ describe('Pi run background lifecycle lease', () => {
     );
     expect(controller.getLeaseCount()).toBe(0);
 
+    workersByConversation.get(runningConversation.id)!.deferNext('compact');
+    const rejectedCompact = runtime.compact(runningConversation.id);
+    void rejectedCompact.catch(() => undefined);
+    await vi.advanceTimersByTimeAsync(0);
+    workersByConversation.get(runningConversation.id)!.emit({
+      type: 'compaction_start',
+      reason: 'manual',
+    });
+    workersByConversation.get(runningConversation.id)!.emit({
+      type: 'compaction_end',
+      reason: 'manual',
+      aborted: false,
+      willRetry: false,
+      errorMessage: 'Compaction failed: controlled rejection',
+    });
+    await vi.advanceTimersByTimeAsync(0);
+    expect((await runtime.getSnapshot(runningConversation.id)).run.status).toBe('error');
+    workersByConversation.get(runningConversation.id)!.rejectDeferred(new PiProcessError(
+      'PI_RPC_RESPONSE_ERROR',
+      'controlled compact rejection',
+      { generation: 1 },
+    ));
+    await expect(rejectedCompact).rejects.toBeInstanceOf(PiProcessError);
+    expect(controller.getLeaseCount()).toBe(0);
+
     await vi.advanceTimersByTimeAsync(100);
     expect(onSleep).toHaveBeenCalledTimes(1);
     expect(onStopRuntime).toHaveBeenCalledTimes(1);