FN-8047: migrate AgentStore multi-node tests to PostgreSQL

Migrate multi-node AgentStore coverage to shared PostgreSQL-backed fixtures.

- Make concurrent central claim insertion resolve unique-key races as checkout conflicts.
- Rework claim and owning-node handoff tests to use shared async PostgreSQL layers.
- Restore PostgreSQL-compatible tests from the quarantine ledger.

Files changed:
 packages/core/src/async-central-db.ts              |  9 ++-
 .../cross-node-claim-mutex.integration.test.ts     | 72 ++++++++++---------
 .../distributed-claim-mutex.integration.test.ts    | 27 +++----
 .../owning-node-handoff.integration.test.ts        | 41 +++++------
 .../__tests__/reliability-interactions/_helpers.ts | 83 ++++++++++++++++++++--
 .../multi-node-claim-mutex-interactions.test.ts    | 28 +++-----
 .../owning-node-unavailable-interactions.test.ts   | 36 +++++-----
 packages/engine/vitest.config.ts                   |  8 +--
 scripts/lib/test-quarantine.json                   | 25 -------
 9 files changed, 180 insertions(+), 149 deletions(-)

Fusion-Task-Id: FN-8047

Fusion-Task-Lineage: 3b7ee21e-0190-4364-a0cb-88aac5e2e1a3

Co-authored-by: Fusion (runfusion.ai) <noreply@runfusion.ai>

packages/engine/src/__tests__/cross-node-claim-mutex.integration.test.ts

@@ -1,35 +1,43 @@
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
-import { mkdtempSync } from "node:fs";
-import { rm } from "node:fs/promises";
-import { join } from "node:path";
-import { tmpdir } from "node:os";
-import { AgentStore, CheckoutConflictError, TaskStore, createCentralDatabase, type CentralDatabase } from "@fusion/core";
+import { AgentStore, AsyncCentralClaimStore, CheckoutConflictError, TaskStore } from "@fusion/core";
+import { pgDescribe } from "../../../core/src/__test-utils__/pg-test-harness.js";
+import { createPgLayer, hasPg, makePgAgentStore, makePgTaskStore } from "./reliability-interactions/_helpers.js";
 
-function makeTmpDir(): string {
-  return mkdtempSync(join(tmpdir(), "fn-cross-node-claim-test-"));
-}
+const pgIt = hasPg ? pgDescribe : describe.skip;
 
-describe("cross-node claim mutex integration", () => {
-  let rootDir: string;
-  let globalDir: string;
+pgIt("cross-node claim mutex integration", () => {
   let taskStore: TaskStore;
-  let centralDb: CentralDatabase;
+  let centralClaimStore: AsyncCentralClaimStore;
   let storeA: AgentStore;
   let storeB: AgentStore;
+  let cleanupTaskStore: (() => Promise<void>) | undefined;
+  let cleanupCentralLayer: (() => Promise<void>) | undefined;
   let agentA: string;
   let agentB: string;
   let taskId: string;
 
   beforeEach(async () => {
-    rootDir = makeTmpDir();
-    globalDir = join(rootDir, ".fusion-global");
-    taskStore = new TaskStore(rootDir, globalDir);
-    await taskStore.init();
-    centralDb = createCentralDatabase(globalDir);
-    centralDb.init();
+    const taskFixture = await makePgTaskStore();
+    const centralFixture = await createPgLayer();
+    taskStore = taskFixture.store;
+    cleanupTaskStore = taskFixture.cleanup;
+    cleanupCentralLayer = centralFixture.cleanup;
+    centralClaimStore = new AsyncCentralClaimStore(centralFixture.layer);
 
-    storeA = new AgentStore({ rootDir, taskStore, claimStore: centralDb, projectId: "P-1", nodeId: "node-a" });
-    storeB = new AgentStore({ rootDir, taskStore, claimStore: centralDb, projectId: "P-1", nodeId: "node-b" });
+    storeA = makePgAgentStore({
+      taskStore,
+      layer: taskFixture.layer,
+      claimStore: centralClaimStore,
+      projectId: "P-1",
+      nodeId: "node-a",
+    });
+    storeB = makePgAgentStore({
+      taskStore,
+      layer: taskFixture.layer,
+      claimStore: centralClaimStore,
+      projectId: "P-1",
+      nodeId: "node-b",
+    });
     await storeA.init();
     await storeB.init();
 
@@ -41,13 +49,12 @@ describe("cross-node claim mutex integration", () => {
   afterEach(async () => {
     storeA?.close();
     storeB?.close();
-    taskStore?.close();
-    centralDb?.close();
-    await rm(rootDir, { recursive: true, force: true, maxRetries: 5, retryDelay: 50 });
+    await cleanupTaskStore?.();
+    await cleanupCentralLayer?.();
   });
 
   it("allows one winner per race and bumps epoch once per successful ownership acquisition", async () => {
-    const originalTryClaim = centralDb.tryClaimTask.bind(centralDb);
+    const originalTryClaim = centralClaimStore.tryClaimTask.bind(centralClaimStore);
     const installBarrier = () => {
       let waiters = 0;
       let releaseBarrier: (() => void) | undefined;
@@ -55,13 +62,14 @@ describe("cross-node claim mutex integration", () => {
         releaseBarrier = resolve;
       });
 
-      centralDb.tryClaimTask = (((input: Parameters<CentralDatabase["tryClaimTask"]>[0]) => {
+      centralClaimStore.tryClaimTask = async (input: Parameters<AsyncCentralClaimStore["tryClaimTask"]>[0]) => {
         waiters += 1;
         if (waiters === 2) {
           releaseBarrier?.();
         }
-        return barrier.then(() => originalTryClaim(input));
-      }) as unknown) as CentralDatabase["tryClaimTask"];
+        await barrier;
+        return originalTryClaim(input);
+      };
     };
 
     installBarrier();
@@ -79,7 +87,7 @@ describe("cross-node claim mutex integration", () => {
 
     const winner = fulfilled[0].value;
     expect(rejected[0].reason.currentHolderId).toBe(winner.checkedOutBy);
-    expect(centralDb.getTaskClaim("P-1", taskId)?.leaseEpoch).toBe(1);
+    expect((await centralClaimStore.getTaskClaim("P-1", taskId))?.leaseEpoch).toBe(1);
     expect(winner.checkoutLeaseEpoch).toBe(1);
     expect(["node-a", "node-b"]).toContain(winner.checkoutNodeId);
 
@@ -97,6 +105,6 @@ describe("cross-node claim mutex integration", () => {
     expect(fulfilled2).toHaveLength(1);
     expect(rejected2).toHaveLength(1);
     expect(rejected2[0].reason).toBeInstanceOf(CheckoutConflictError);
-    expect(centralDb.getTaskClaim("P-1", taskId)?.leaseEpoch).toBe(1);
+    expect((await centralClaimStore.getTaskClaim("P-1", taskId))?.leaseEpoch).toBe(1);
   });
 });

packages/engine/src/__tests__/distributed-claim-mutex.integration.test.ts

@@ -1,29 +1,23 @@
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
-import { mkdtempSync } from "node:fs";
-import { rm } from "node:fs/promises";
-import { join } from "node:path";
-import { tmpdir } from "node:os";
 import { AgentStore, CheckoutConflictError, TaskStore } from "@fusion/core";
+import { pgDescribe } from "../../../core/src/__test-utils__/pg-test-harness.js";
+import { hasPg, makePgAgentStore, makePgTaskStore } from "./reliability-interactions/_helpers.js";
 
-function makeTmpDir(): string {
-  return mkdtempSync(join(tmpdir(), "fn-distributed-claim-test-"));
-}
+const pgIt = hasPg ? pgDescribe : describe.skip;
 
-describe("distributed claim mutex integration", () => {
-  let rootDir: string;
+pgIt("distributed claim mutex integration", () => {
   let taskStore: TaskStore;
   let agentStore: AgentStore;
+  let cleanup: (() => Promise<void>) | undefined;
   let winnerAgentId = "";
-  let globalDir = "";
   let loserAgentId = "";
   let taskId = "";
 
   beforeEach(async () => {
-    rootDir = makeTmpDir();
-    globalDir = join(rootDir, ".fusion-global");
-    taskStore = new TaskStore(rootDir, globalDir);
-    await taskStore.init();
-    agentStore = new AgentStore({ rootDir, taskStore });
+    const fixture = await makePgTaskStore();
+    taskStore = fixture.store;
+    cleanup = fixture.cleanup;
+    agentStore = makePgAgentStore({ taskStore, layer: fixture.layer });
     await agentStore.init();
 
     winnerAgentId = (await agentStore.createAgent({ name: "winner", role: "executor" })).id;
@@ -33,8 +27,7 @@ describe("distributed claim mutex integration", () => {
 
   afterEach(async () => {
     agentStore?.close();
-    taskStore?.close();
-    await rm(rootDir, { recursive: true, force: true, maxRetries: 5, retryDelay: 50 });
+    await cleanup?.();
   });
 
   it("allows exactly one concurrent claimant and supports retry after release", async () => {

packages/engine/src/__tests__/owning-node-handoff.integration.test.ts

@@ -1,33 +1,26 @@
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
-import { mkdtempSync } from "node:fs";
-import { rm } from "node:fs/promises";
-import { join } from "node:path";
-import { tmpdir } from "node:os";
 import { TaskStore, type OwningNodeHandoffPolicy } from "@fusion/core";
+import { pgDescribe } from "../../../core/src/__test-utils__/pg-test-harness.js";
+import { hasPg, makePgTaskStore } from "./reliability-interactions/_helpers.js";
 import { MeshLeaseManager } from "../mesh-lease-manager.js";
 import type { NodeHealthMonitor } from "../node-health-monitor.js";
 
-function makeTmpDir(): string {
-  return mkdtempSync(join(tmpdir(), "fn-owning-handoff-test-"));
-}
+const pgIt = hasPg ? pgDescribe : describe.skip;
 
-describe("MeshLeaseManager owning-node handoff integration", () => {
-  let rootDir: string;
-  let globalDir: string;
+pgIt("MeshLeaseManager owning-node handoff integration", () => {
   let taskStore: TaskStore;
+  let cleanup: (() => Promise<void>) | undefined;
   let taskId: string;
 
   beforeEach(async () => {
-    rootDir = makeTmpDir();
-    globalDir = join(rootDir, ".fusion-global");
-    taskStore = new TaskStore(rootDir, globalDir);
-    await taskStore.init();
+    const fixture = await makePgTaskStore();
+    taskStore = fixture.store;
+    cleanup = fixture.cleanup;
     taskId = (await taskStore.createTask({ description: "handoff" })).id;
   });
 
   afterEach(async () => {
-    taskStore?.close();
-    await rm(rootDir, { recursive: true, force: true, maxRetries: 5, retryDelay: 50 });
+    await cleanup?.();
   });
 
   async function seedLease(ownerNodeId: string): Promise<void> {
@@ -54,20 +47,20 @@ describe("MeshLeaseManager owning-node handoff integration", () => {
 
   it("applies handoff policy matrix for peer-owned leases", async () => {
     await seedLease("node-peer");
-    let baselineEventIds = new Set(taskStore.getRunAuditEvents({ taskId, limit: 200 }).map((event) => event.id));
+    let baselineEventIds = new Set((await taskStore.getRunAuditEventsAsync({ taskId, limit: 200 })).map((event) => event.id));
     expect(await runCase("block", "node-peer")).toBe(false);
     let task = await taskStore.getTask(taskId);
     expect(task?.checkedOutBy).toBe("agent-1");
-    let newEvents = taskStore.getRunAuditEvents({ taskId, limit: 200 }).filter((event) => !baselineEventIds.has(event.id));
+    let newEvents = (await taskStore.getRunAuditEventsAsync({ taskId, limit: 200 })).filter((event) => !baselineEventIds.has(event.id));
     expect(newEvents.some((event) => event.mutationType === "node:handoff:parked" && event.metadata?.source === "mesh-lease.recover" && event.metadata?.decisionReason === "handoff_blocked_by_policy")).toBe(true);
     expect(newEvents.some((event) => event.mutationType === "node:lease:recovered")).toBe(false);
 
     await seedLease("node-peer");
-    baselineEventIds = new Set(taskStore.getRunAuditEvents({ taskId, limit: 200 }).map((event) => event.id));
+    baselineEventIds = new Set((await taskStore.getRunAuditEventsAsync({ taskId, limit: 200 })).map((event) => event.id));
     expect(await runCase("reassign-to-local", "node-peer")).toBe(true);
     task = await taskStore.getTask(taskId);
     expect(task?.checkedOutBy ?? null).toBeNull();
-    newEvents = taskStore.getRunAuditEvents({ taskId, limit: 200 }).filter((event) => !baselineEventIds.has(event.id));
+    newEvents = (await taskStore.getRunAuditEventsAsync({ taskId, limit: 200 })).filter((event) => !baselineEventIds.has(event.id));
     const localRecoveryEvent = newEvents.find((event) => event.mutationType === "node:lease:recovered");
     expect(localRecoveryEvent).toBeTruthy();
     expect(localRecoveryEvent?.metadata?.source).toBe("mesh-lease.recover");
@@ -75,11 +68,11 @@ describe("MeshLeaseManager owning-node handoff integration", () => {
     expect(String(localRecoveryEvent?.metadata?.recoveryReason ?? "")).toContain("test-owner-unavailable");
 
     await seedLease("node-peer");
-    baselineEventIds = new Set(taskStore.getRunAuditEvents({ taskId, limit: 200 }).map((event) => event.id));
+    baselineEventIds = new Set((await taskStore.getRunAuditEventsAsync({ taskId, limit: 200 })).map((event) => event.id));
     expect(await runCase("reassign-any-healthy", "node-peer")).toBe(true);
     task = await taskStore.getTask(taskId);
     expect(task?.checkedOutBy ?? null).toBeNull();
-    newEvents = taskStore.getRunAuditEvents({ taskId, limit: 200 }).filter((event) => !baselineEventIds.has(event.id));
+    newEvents = (await taskStore.getRunAuditEventsAsync({ taskId, limit: 200 })).filter((event) => !baselineEventIds.has(event.id));
     const anyRecoveryEvent = newEvents.find((event) => event.mutationType === "node:lease:recovered");
     expect(anyRecoveryEvent).toBeTruthy();
     expect(anyRecoveryEvent?.metadata?.source).toBe("mesh-lease.recover");
@@ -90,12 +83,12 @@ describe("MeshLeaseManager owning-node handoff integration", () => {
   it("recovers self-owned leases regardless of policy", async () => {
     for (const policy of ["block", "reassign-to-local", "reassign-any-healthy"] as const) {
       await seedLease("node-local");
-      const baselineEventIds = new Set(taskStore.getRunAuditEvents({ taskId, limit: 200 }).map((event) => event.id));
+      const baselineEventIds = new Set((await taskStore.getRunAuditEventsAsync({ taskId, limit: 200 })).map((event) => event.id));
       const recovered = await runCase(policy, "node-local");
       expect(recovered).toBe(true);
       const task = await taskStore.getTask(taskId);
       expect(task?.checkedOutBy ?? null).toBeNull();
-      const newEvents = taskStore.getRunAuditEvents({ taskId, limit: 200 }).filter((event) => !baselineEventIds.has(event.id));
+      const newEvents = (await taskStore.getRunAuditEventsAsync({ taskId, limit: 200 })).filter((event) => !baselineEventIds.has(event.id));
       const recoveryEvents = newEvents.filter((event) => event.mutationType === "node:lease:recovered");
       expect(recoveryEvents).toHaveLength(1);
       expect(recoveryEvents[0]?.metadata?.source).toBe("mesh-lease.recover");

packages/engine/src/__tests__/reliability-interactions/_helpers.ts

@@ -4,8 +4,8 @@ import { join } from "node:path";
 import { execSync, spawnSync, exec } from "node:child_process";
 import { Worker } from "node:worker_threads";
 import {
-  DEFAULT_SETTINGS, TaskStore, type Settings, type Task,
-  type AsyncDataLayer, type ResolvedBackend,
+  AgentStore, DEFAULT_SETTINGS, TaskStore, type Settings, type Task,
+  type AsyncDataLayer, type CentralClaimStore, type ResolvedBackend,
   createConnectionSetFromUrl, applySchemaBaseline, createAsyncDataLayer,
 } from "@fusion/core";
 import { aiMergeTask } from "../../merger.js";
@@ -131,7 +131,18 @@ function adminExecAsync(statement: string, timeoutMs = 15_000): Promise<void> {
 
 let relDbCounter = 0;
 
-async function createPgLayer(): Promise<{ layer: AsyncDataLayer; dbName: string }> {
+export type PgLayerFixture = {
+  layer: AsyncDataLayer;
+  dbName: string;
+  cleanup: () => Promise<void>;
+};
+
+/**
+ * Create one isolated PostgreSQL schema layer for a reliability test.
+ * Callers must use {@link hasPg} before invoking this helper because DDL uses
+ * the `psql` binary as well as a TCP-reachable PostgreSQL server.
+ */
+export async function createPgLayer(): Promise<PgLayerFixture> {
   relDbCounter += 1;
   const dbName = `fusion_rel_${process.pid}_${relDbCounter}_${Math.random().toString(36).slice(2, 8)}`;
   try {
@@ -152,7 +163,65 @@ async function createPgLayer(): Promise<{ layer: AsyncDataLayer; dbName: string
   await schemaConn.close();
   const connections = await createConnectionSetFromUrl(backend, { poolMax: 5, connectTimeoutSeconds: 5 });
   const layer = createAsyncDataLayer(connections);
-  return { layer, dbName };
+  return {
+    layer,
+    dbName,
+    cleanup: async () => {
+      try { await layer.close(); } catch { /* best-effort */ }
+      try { await adminExecAsync(`DROP DATABASE IF EXISTS "${dbName}"`); } catch { /* best-effort */ }
+    },
+  };
+}
+
+/*
+FNXC:PgMigrationQuarantine 2026-07-16-10:30:
+VAL-REMOVAL-005 removed AgentStore's SQLite runtime path, so multi-node claim and handoff tests must construct TaskStore and every sibling AgentStore with one shared AsyncDataLayer. Reliability callers gate with hasGit && hasPg; integration callers compose hasPg ? pgDescribe : describe.skip because DDL requires both reachable PostgreSQL and psql, but integration tests do not require Git.
+*/
+export async function makePgTaskStore(): Promise<{
+  rootDir: string;
+  store: TaskStore;
+  layer: AsyncDataLayer;
+  cleanup: () => Promise<void>;
+}> {
+  const rootDir = await mkdtemp(join(reliabilityTestTempParent(), "fusion-pg-store-"));
+  const pg = await createPgLayer();
+  const store = new TaskStore(rootDir, undefined, { asyncLayer: pg.layer });
+  await store.init();
+  return {
+    rootDir,
+    store,
+    layer: pg.layer,
+    cleanup: async () => {
+      await store.close();
+      await pg.cleanup();
+      await rm(rootDir, { recursive: true, force: true });
+    },
+  };
+}
+
+/**
+ * Construct one backend-mode AgentStore for each AgentStore instance a test
+ * already needs. Two-store tests call this twice with the same taskStore/layer.
+ */
+export function makePgAgentStore(input: {
+  taskStore: TaskStore;
+  layer: AsyncDataLayer;
+  rootDir?: string;
+  claimStore?: CentralClaimStore;
+  projectId?: string;
+  nodeId?: string;
+}): AgentStore {
+  if (input.taskStore.getAsyncLayer() !== input.layer) {
+    throw new Error("makePgAgentStore requires the TaskStore's shared asyncLayer");
+  }
+  return new AgentStore({
+    rootDir: input.rootDir ?? input.taskStore.getRootDir(),
+    taskStore: input.taskStore,
+    asyncLayer: input.layer,
+    claimStore: input.claimStore,
+    projectId: input.projectId,
+    nodeId: input.nodeId,
+  });
 }
 
 export type ReliabilityFixture = {
@@ -194,7 +263,8 @@ export async function makeReliabilityFixture(input: {
   git(rootDir, 'git commit -m "chore: init"');
   await mkdir(join(rootDir, ".fusion"), { recursive: true });
 
-  const { layer, dbName } = await createPgLayer();
+  const pg = await createPgLayer();
+  const { layer } = pg;
   const store = new TaskStore(rootDir, undefined, { asyncLayer: layer });
   await store.init();
   const settings: Settings = {
@@ -232,8 +302,7 @@ export async function makeReliabilityFixture(input: {
     cleanup: async () => {
       manager.stop();
       await store.close();
-      try { await layer.close(); } catch { /* best-effort */ }
-      try { await adminExecAsync(`DROP DATABASE IF EXISTS "${dbName}"`); } catch { /* best-effort */ }
+      await pg.cleanup();
       await rm(rootDir, { recursive: true, force: true });
       await rm(worktreeRoot, { recursive: true, force: true });
     },

packages/engine/src/__tests__/reliability-interactions/multi-node-claim-mutex-interactions.test.ts

@@ -1,18 +1,12 @@
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
-import { mkdtempSync } from "node:fs";
-import { rm } from "node:fs/promises";
-import { join } from "node:path";
-import { tmpdir } from "node:os";
 import { AgentStore, CheckoutConflictError, TaskStore } from "@fusion/core";
+import { hasGit, hasPg, makePgAgentStore, makePgTaskStore } from "./_helpers.js";
 
-function makeTmpDir(): string {
-  return mkdtempSync(join(tmpdir(), "fn-reliability-claim-mutex-"));
-}
+const describeIfGit = hasGit && hasPg ? describe : describe.skip;
 
-describe("reliability interactions: multi-node claim mutex", () => {
-  let rootDir: string;
-  let globalDir: string;
+describeIfGit("reliability interactions: multi-node claim mutex", () => {
   let taskStore: TaskStore;
+  let cleanup: (() => Promise<void>) | undefined;
   let agentStoreA: AgentStore;
   let agentStoreB: AgentStore;
   let taskId: string;
@@ -20,13 +14,12 @@ describe("reliability interactions: multi-node claim mutex", () => {
   let agentB: string;
 
   beforeEach(async () => {
-    rootDir = makeTmpDir();
-    globalDir = join(rootDir, ".fusion-global");
-    taskStore = new TaskStore(rootDir, globalDir);
-    await taskStore.init();
+    const fixture = await makePgTaskStore();
+    taskStore = fixture.store;
+    cleanup = fixture.cleanup;
 
-    agentStoreA = new AgentStore({ rootDir, taskStore });
-    agentStoreB = new AgentStore({ rootDir, taskStore });
+    agentStoreA = makePgAgentStore({ taskStore, layer: fixture.layer });
+    agentStoreB = makePgAgentStore({ taskStore, layer: fixture.layer });
     await agentStoreA.init();
     await agentStoreB.init();
 
@@ -38,8 +31,7 @@ describe("reliability interactions: multi-node claim mutex", () => {
   afterEach(async () => {
     agentStoreA?.close();
     agentStoreB?.close();
-    taskStore?.close();
-    await rm(rootDir, { recursive: true, force: true, maxRetries: 5, retryDelay: 50 });
+    await cleanup?.();
   });
 
   it("prevents split-brain, preserves renewal semantics, and keeps legacy conflict shape", async () => {

packages/engine/src/__tests__/reliability-interactions/owning-node-unavailable-interactions.test.ts

@@ -1,13 +1,13 @@
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
-import { existsSync, mkdtempSync } from "node:fs";
-import { readFile } from "node:fs/promises";
-import { rm } from "node:fs/promises";
-import { join } from "node:path";
-import { tmpdir } from "node:os";
+import { existsSync } from "node:fs";
 import type { NodeStatus, OwningNodeHandoffPolicy, Task, TaskStore } from "@fusion/core";
 import { TaskStore as CoreTaskStore } from "@fusion/core";
 import { MeshLeaseManager } from "../../mesh-lease-manager.js";
 import { Scheduler } from "../../scheduler.js";
+import { hasGit, hasPg, makePgTaskStore } from "./_helpers.js";
+
+const describeIfGit = hasGit && hasPg ? describe : describe.skip;
+const readFileState = vi.hoisted(() => ({ mockPromptRead: false }));
 
 vi.mock("node:fs", async (importOriginal) => {
   const actual = await importOriginal<typeof import("node:fs")>();
@@ -21,14 +21,12 @@ vi.mock("node:fs/promises", async (importOriginal) => {
   const actual = await importOriginal<typeof import("node:fs/promises")>();
   return {
     ...actual,
-    readFile: vi.fn(),
+    readFile: async (...args: Parameters<typeof actual.readFile>) => (
+      readFileState.mockPromptRead ? "# Task\nFN-4813" : actual.readFile(...args)
+    ),
   };
 });
 
-function makeTmpDir(): string {
-  return mkdtempSync(join(tmpdir(), "fn-owning-node-handoff-"));
-}
-
 function createMockTask(overrides: Partial<Task> = {}): Task {
   return {
     id: "FN-200",
@@ -72,23 +70,21 @@ function createMockHealthMonitor(statusMap: Record<string, NodeStatus | undefine
   } as unknown as import("../../node-health-monitor.js").NodeHealthMonitor;
 }
 
-describe("reliability interactions: owning-node unavailable handoff", () => {
-  let rootDir = "";
-  let globalDir = "";
+describeIfGit("reliability interactions: owning-node unavailable handoff", () => {
   let taskStore: CoreTaskStore;
+  let cleanup: (() => Promise<void>) | undefined;
 
   beforeEach(async () => {
     vi.mocked(existsSync).mockReturnValue(true);
-    vi.mocked(readFile).mockResolvedValue("# Task\nFN-4813");
-    rootDir = makeTmpDir();
-    globalDir = join(rootDir, ".fusion-global");
-    taskStore = new CoreTaskStore(rootDir, globalDir);
-    await taskStore.init();
+    const fixture = await makePgTaskStore();
+    taskStore = fixture.store;
+    cleanup = fixture.cleanup;
+    readFileState.mockPromptRead = true;
   });
 
   afterEach(async () => {
-    taskStore?.close();
-    await rm(rootDir, { recursive: true, force: true, maxRetries: 5, retryDelay: 50 });
+    readFileState.mockPromptRead = false;
+    await cleanup?.();
   });
 
   async function seedCheckedOutTask(overrides: Partial<Task> = {}): Promise<Task> {

packages/engine/vitest.config.ts

@@ -301,11 +301,8 @@ export default defineConfig({
             // getDatabase, walCheckpoint) that throw/return-empty in backend mode, or have mock
             // drift from the async-satellite cutover. Quarantined on sight per AGENTS.md.
             "src/__tests__/backlog-pressure-reporter.test.ts",
-            "src/__tests__/cross-node-claim-mutex.integration.test.ts",
-            "src/__tests__/distributed-claim-mutex.integration.test.ts",
             "src/__tests__/mission-autopilot.test.ts",
             "src/__tests__/mission-factory-parity.integration.test.ts",
-            "src/__tests__/owning-node-handoff.integration.test.ts",
             "src/__tests__/planner-overseer-intervention-wiring.test.ts",
             "src/__tests__/project-engine.test.ts",
             "src/__tests__/self-healing.test.ts",
@@ -379,8 +376,9 @@ export default defineConfig({
             // (now PG-backed) but fail on sync SQLite APIs (getRunAuditEvents, getDatabase) that
             // return [] / throw in backend mode, or on mock drift from the async-satellite cutover.
             // Quarantined on sight per AGENTS.md; mirrored in scripts/lib/test-quarantine.json.
-            "src/__tests__/reliability-interactions/multi-node-claim-mutex-interactions.test.ts",
-            "src/__tests__/reliability-interactions/owning-node-unavailable-interactions.test.ts",
+            // FNXC:PgMigrationQuarantine 2026-07-16-10:45:
+            // FN-8047 restored multi-node claim and owning-node handoff coverage with shared PG-backed
+            // AgentStores and AsyncCentralClaimStore; their paired ledger entries are intentionally live.
             "src/__tests__/reliability-interactions/integration-worktree-state.test.ts",
             "src/__tests__/reliability-interactions/explicit-duplicate-marker-sweep.test.ts",
             "src/__tests__/reliability-interactions/self-defeating-dep-reconcile.test.ts",