feat(FN-5436): skip step retries when review is pending

Added executor logic to skip retries when a review is pending for a task, introducing a `pendingReviewBlockHelper` in the task-done path and updating the retry-gate to consult it; two new reliability-interaction test suites cover the feature behavior and composition with existing retry/backstop laye

Fusion-Task-Id: FN-5436

packages/engine/src/__tests__/reliability-interactions/executor-pending-review-skip-retry.test.ts

@@ -0,0 +1,134 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import "../executor-test-helpers.js";
+import { TaskExecutor } from "../../executor.js";
+import { createFnAgent } from "../../pi.js";
+import { createMockStore, resetExecutorMocks } from "../executor-test-helpers.js";
+
+const mockedCreateFnAgent = vi.mocked(createFnAgent);
+
+function makeTask(overrides: Record<string, unknown> = {}) {
+  return {
+    id: "FN-5436-RI",
+    title: "Pending review skip",
+    description: "",
+    column: "in-progress",
+    dependencies: [],
+    taskDoneRetryCount: 0,
+    steps: [{ name: "Step 1", status: "in-progress" as const }],
+    currentStep: 0,
+    log: [],
+    prompt: "# test\n## Steps\n### Step 1: Step 1\n- [ ] do work",
+    createdAt: new Date().toISOString(),
+    updatedAt: new Date().toISOString(),
+    ...overrides,
+  } as any;
+}
+
+describe("reliability interactions: FN-5436 executor pending-review skip", () => {
+  beforeEach(() => {
+    resetExecutorMocks();
+    mockedCreateFnAgent.mockResolvedValue({
+      session: {
+        prompt: vi.fn().mockResolvedValue(undefined),
+        dispose: vi.fn(),
+        subscribe: vi.fn(),
+        on: vi.fn(),
+        sessionManager: { getLeafId: vi.fn().mockReturnValue("leaf-1") },
+        state: {},
+      },
+    } as any);
+  });
+
+  it("FN-5436 composition: implicit-done wins when no in-progress step exists despite stale review logs", async () => {
+    const store = createMockStore();
+    const task = makeTask({
+      id: "FN-5436-RI-A",
+      steps: [{ name: "Step 1", status: "done" }],
+      log: [{ action: "code review Step 1: REVISE", timestamp: new Date().toISOString() }],
+    });
+    store.getTask.mockResolvedValue(task);
+
+    const executor = new TaskExecutor(store as any, "/repo");
+    await executor.execute(task);
+
+    expect(store.updateTask).not.toHaveBeenCalledWith("FN-5436-RI-A", {
+      status: "failed",
+      error: "executor-exit-while-review-pending",
+    });
+    expect(store.moveTask).toHaveBeenCalledWith("FN-5436-RI-A", "in-review");
+  });
+
+  it("FN-5436 composition: reclaim-abort path takes precedence over pending-review skip", async () => {
+    const store = createMockStore();
+    const task = makeTask({ id: "FN-5436-RI-B", paused: true });
+    store.getTask.mockResolvedValue(task);
+
+    const executor = new TaskExecutor(store as any, "/repo");
+    await executor.execute(task);
+
+    expect(store.moveTask).toHaveBeenCalledWith("FN-5436-RI-B", "todo", { preserveProgress: true });
+    expect(store.updateTask).not.toHaveBeenCalledWith("FN-5436-RI-B", {
+      status: "failed",
+      error: "executor-exit-while-review-pending",
+    });
+  });
+
+  it("FN-5436 composition: pending-review park does not consume taskDone requeue budget", async () => {
+    const store = createMockStore();
+    const task = makeTask({
+      id: "FN-5436-RI-C",
+      taskDoneRetryCount: 2,
+      log: [{ action: "code review requested for Step 1 (Step 1)", timestamp: new Date().toISOString() }],
+    });
+    store.getTask.mockResolvedValue(task);
+
+    const executor = new TaskExecutor(store as any, "/repo");
+    await executor.execute(task);
+
+    expect(store.updateTask).toHaveBeenCalledWith("FN-5436-RI-C", {
+      status: "failed",
+      error: "executor-exit-while-review-pending",
+    });
+    expect(store.updateTask).not.toHaveBeenCalledWith("FN-5436-RI-C", expect.objectContaining({ taskDoneRetryCount: 3 }));
+    expect(store.moveTask).toHaveBeenCalledWith("FN-5436-RI-C", "in-review");
+  });
+
+  it("FN-5436 composition: recoverApprovedStepsOnResume leaves pending-review skip disabled after approval resolves step", async () => {
+    const store = createMockStore();
+    const task = makeTask({
+      id: "FN-5436-RI-D",
+      steps: [{ name: "Step 1", status: "done" }],
+      log: [{ action: "code review Step 1: APPROVE", timestamp: new Date().toISOString() }],
+    });
+    store.getTask.mockResolvedValue(task);
+
+    const executor = new TaskExecutor(store as any, "/repo");
+    await executor.execute(task);
+
+    expect(store.updateTask).toHaveBeenCalledWith("FN-5436-RI-D", { workflowStepRetries: undefined, taskDoneRetryCount: null });
+    expect(store.updateTask).not.toHaveBeenCalledWith("FN-5436-RI-D", {
+      status: "failed",
+      error: "executor-exit-while-review-pending",
+    });
+    expect(store.moveTask).toHaveBeenCalledWith("FN-5436-RI-D", "in-review");
+  });
+
+  it("FN-5436 negative: plan-review UNAVAILABLE advisory remains non-blocking", async () => {
+    const store = createMockStore();
+    const task = makeTask({
+      id: "FN-5436-RI-E",
+      log: [{ action: "plan review Step 1: UNAVAILABLE — proceeding advisory after fallback retry exhausted", timestamp: new Date().toISOString() }],
+    });
+    store.getTask.mockResolvedValue(task);
+
+    const executor = new TaskExecutor(store as any, "/repo");
+    await executor.execute(task);
+
+    expect(mockedCreateFnAgent).toHaveBeenCalledTimes(4);
+    expect(store.updateTask).toHaveBeenCalledWith("FN-5436-RI-E", {
+      status: "failed",
+      error: "Agent finished without calling fn_task_done (after 3 retries)",
+      taskDoneRetryCount: 1,
+    });
+  });
+});