FN-6954: reconcile stale parked task assignments

Reconcile agent/task drift when durable agents remain linked to queued tasks without live execution proof. - clear stale Agent.taskId links for parked todo/triage tasks while preserving task leases and queue state - report stale parked assignments as active/no-live-run in Reports Health Check before reconciliation completes - add scheduler and self-healing coverage for queued lease drift, overlap starvation, and audit events - document the reconciliation behavior and add a published package patch changeset Files changed: .changeset/fn-6954-agent-task-state-drift.md | 5 + docs/architecture.md | 2 + .../src/__tests__/heartbeat-executor.test.ts | 68 ++++++++++++ .../__tests__/scheduler-overlap-starvation.test.ts | 68 +++++++++++- .../self-healing-agent-link-drift.test.ts | 97 ++++++++++++++++- .../engine/src/__tests__/task-agent-sync.test.ts | 33 +++++- packages/engine/src/agent-heartbeat.ts | 121 +++++++++++++++++++-- packages/engine/src/run-audit.ts | 5 + packages/engine/src/runtimes/in-process-runtime.ts | 1 + packages/engine/src/scheduler.ts | 24 +++- packages/engine/src/self-healing.ts | 102 ++++++++++++++--- packages/engine/src/task-agent-sync.ts | 65 ++++++++++- 12 files changed, 555 insertions(+), 36 deletions(-) Fusion-Task-Id: FN-6954 Fusion-Task-Lineage: 24b8a2eb-5a33-4539-ab64-ae2bbfc2d195
2026-06-23 09:48:15 -07:00
parent 81f43e0e89
commit fe536b2af8
12 changed files with 555 additions and 36 deletions
--- a/.changeset/fn-6954-agent-task-state-drift.md
+++ b/.changeset/fn-6954-agent-task-state-drift.md
@@ -0,0 +1,5 @@
+---
+"@runfusion/fusion": patch
+---
+
+Fix stale durable agent task assignments for tasks parked behind file-scope lease queues, including Reports Health Check rendering and self-healing reconciliation.
--- a/docs/architecture.md
+++ b/docs/architecture.md
@@ -682,6 +682,7 @@ Runtime action-gate flow (v1):
  - `recoverGhostReviewTasks()` is a fallback only for idle, non-terminal `in-review` states. Terminal/actionable states (notably `status: "failed"`) are preserved and **not** auto-kicked back to `todo`.
  - `recoverPausedAbortFailures()` clears executor pause/resume abort parks only when the durable row is safe to recover. `todo`/`in-progress` rows are requeued for normal scheduling, while clean `in-review` rows (completed steps, not paused/user-paused/executing, auto-merge eligible, no confirmed or terminal merge evidence) have `status`/`error` cleared in place so review progression can continue. User hard-cancel, global/user pause, `autoMerge:false`, terminal merge, and live-execution guards remain operator-actionable. Successful recovery emits `task:auto-recover-paused-abort-park` with `preservedInReview` metadata.
  - `reattach-orphaned-assigned-executions` is a forward-resume safety net for durable-agent assignments. During startup recovery and periodic maintenance, after orphaned-agent and stale-heartbeat-run repairs, self-healing finds `in-progress` tasks with an `assignedAgentId` whose agent has no active heartbeat run and no active executor session after the orphan grace window. It re-dispatches in place via `executor.resumeTaskForAgent(agentId)` (the same seam used by clean `HeartbeatMonitor.onRunCompleted` and guarded by executor double-execution checks), emits `task:reattach-orphaned-execution`, and never moves the task backward. This complements engine-start `executor.resumeOrphaned()` and leaves unassigned/role-based execution recovery to the existing startup/limbo/stuck-task paths.
+  - Durable `Agent.taskId` is a running assignment for parked `todo`/`triage` task rows only when the agent has live proof: a fresh active heartbeat run or an executor-active/tracked heartbeat signal. Scheduler overlap requeues, task move sync, self-healing, and Reports Health Check share this invariant: stale durable links are cleared or rendered as stale while `status: "queued"` and `overlapBlockedBy` remain on the task row so file-scope lease blocking is not weakened.
  - Mission validation has a dedicated stale-run reaper: startup recovery and Batch 2 maintenance call `reapStaleMissionValidatorRuns()` when wired by the runtime, using `VALIDATOR_RUN_STALE_MAX_AGE_MS` (currently 6 hours). The sweep terminates ownerless `mission_validator_runs.status='running'` rows as `error`, writes the reap reason into `summary`, leaves `lastValidatorRunId` pointing at the now-terminal run, and emits run-audit telemetry with `mutationType: "mission:validator-run-reaped"` plus `runId`/`featureId`/`missionId`/`triggerType`/`elapsedMs` metadata. Active mission features move to `loopState="needs_fix"` + `lastValidatorStatus="error"` unless their parent mission is already `complete`/`archived`.

 #### Stuck-loop exhaustion terminal contract
@@ -1091,6 +1092,7 @@ The run-audit system records every mutation performed by the engine across four
 - **Database / `task:no-commits-finalize-blocked-incomplete-steps`** — emitted by no-op finalize lanes when a `noCommitsExpected` task has no net branch changes but incomplete/skipped steps outweigh done steps. Metadata includes `{ reason, doneCount, incompleteCount, lane, classification?, baseRef? }`; the accompanying task log explains that the task was demoted to `todo` with progress preserved instead of finalized as done.
 - **Database / `task:orphan-detected-no-action`** — emitted by `recoverOrphanedExecutions` (FN-5337) when row metadata looks orphaned after grace windows; annotation-only event with no lifecycle mutation (`in-progress` task stays put).
 - **Database / `task:reattach-orphaned-execution`** — emitted by `reattachOrphanedAssignedExecutions` (FN-6336) when self-healing re-dispatches an idle assigned `in-progress` task forward via `executor.resumeTaskForAgent(agentId)` after proving the assigned agent has no active heartbeat run or active execution.
+- **Database / `task:reconcile-stale-agent-assignment`** — emitted when self-healing or heartbeat reconciliation clears stale durable `Agent.taskId`/`state` for a task parked in `todo`/`triage` without live execution proof. Metadata includes `{ agentId, taskId, taskColumn, agentState, status, blockedBy, overlapBlockedBy, hadFreshRun, hadActiveExecution, reason }`; task queue/lease fields are preserved.
 - **Database / `task:soft-delete-column-reconciled`** — emitted by `reconcileSoftDeletedColumnDrift` (FN-5566, re-land FN-5446) when a soft-deleted row (`deletedAt IS NOT NULL`) is found with legacy `column != 'archived'`; rewrites only `column` (no resurrection), with metadata `{ previousColumn }`.
 - **Database / `session:runtime-resolved`** — emitted once per `createResolvedAgentSession` call with metadata `{ sessionPurpose, runtimeId, wasConfigured, provider, modelId, mockProviderActive, testModeActive, runtimeHint? }` for per-lane runtime/provider attribution.
 - **Database / `task:reconcile-dependency-blocking-lease`** — emitted by `reconcileDependencyBlockingLeases()` (FN-6292) when self-healing rebounds an `in-progress` holder to `todo` because an unmet dependency is blocked by the holder's stale file-scope lease. Metadata includes the dependency ID, blocked-by marker, and unmet dependency list.
--- a/packages/engine/src/tests/heartbeat-executor.test.ts
+++ b/packages/engine/src/tests/heartbeat-executor.test.ts
@@ -190,6 +190,8 @@ describe("executeHeartbeat", () => {
      setLastBlockedState: vi.fn().mockResolvedValue(undefined),
      clearLastBlockedState: vi.fn().mockResolvedValue(undefined),
      appendRunLog: vi.fn().mockResolvedValue(undefined),
+      getActiveHeartbeatRun: vi.fn().mockResolvedValue(null),
+      syncExecutionTaskLink: vi.fn().mockResolvedValue(undefined),
      getAgentsByReportsTo: vi.fn().mockResolvedValue([]),
    } as unknown as AgentStore;
  }
@@ -236,6 +238,72 @@ describe("executeHeartbeat", () => {
      expect(section).toContain("healthy");
    });

+    it("FN-6954: buildReportsHealthSection suppresses running state for parked task with no live proof", async () => {
+      const now = new Date().toISOString();
+      const store = createStoreWithAgentForExec();
+      vi.mocked(store.getAgentsByReportsTo).mockResolvedValue([
+        { id: "agent-backend", name: "Backend Engineer", state: "running", taskId: "FN-6709", lastHeartbeatAt: now, updatedAt: now } as Agent,
+      ]);
+      vi.mocked(store.getActiveHeartbeatRun).mockResolvedValue(null);
+      mockTaskStore = createMockTaskStore({
+        getTask: vi.fn(async (taskId: string) => ({
+          id: taskId,
+          column: "todo",
+          status: "queued",
+          overlapBlockedBy: "FN-6827",
+          blockedBy: null,
+          dependencies: [],
+          log: [],
+          steps: [],
+          attachments: [],
+          createdAt: now,
+          updatedAt: now,
+        }) as unknown as TaskDetail),
+      });
+      const monitor = new HeartbeatMonitor({ store, taskStore: mockTaskStore, rootDir: "/tmp" });
+
+      const section = await (monitor as any).buildReportsHealthSection("agent-001", store);
+
+      expect(section).toContain("| Backend Engineer | active | FN-6709 (queued/no live run) |");
+      expect(section).toContain("**stale** assignment");
+      expect(section).not.toContain("| Backend Engineer | running | FN-6709 |");
+    });
+
+    it("FN-6954: buildReportsHealthSection preserves running state for parked task with fresh active run", async () => {
+      const now = new Date().toISOString();
+      const store = createStoreWithAgentForExec();
+      vi.mocked(store.getAgentsByReportsTo).mockResolvedValue([
+        { id: "agent-backend", name: "Backend Engineer", state: "running", taskId: "FN-6709", lastHeartbeatAt: now, updatedAt: now } as Agent,
+      ]);
+      vi.mocked(store.getActiveHeartbeatRun).mockResolvedValue({
+        id: "run-live",
+        agentId: "agent-backend",
+        startedAt: now,
+        status: "active",
+      } as AgentHeartbeatRun);
+      mockTaskStore = createMockTaskStore({
+        getTask: vi.fn(async (taskId: string) => ({
+          id: taskId,
+          column: "todo",
+          status: "queued",
+          overlapBlockedBy: "FN-6827",
+          dependencies: [],
+          log: [],
+          steps: [],
+          attachments: [],
+          createdAt: now,
+          updatedAt: now,
+        }) as unknown as TaskDetail),
+      });
+      const monitor = new HeartbeatMonitor({ store, taskStore: mockTaskStore, rootDir: "/tmp" });
+
+      const section = await (monitor as any).buildReportsHealthSection("agent-001", store);
+
+      expect(section).toContain("| Backend Engineer | running | FN-6709 |");
+      expect(section).not.toContain("queued/no live run");
+      expect(section).not.toContain("**stale** assignment");
+    });
+
    it("buildReportsHealthSection classifies stuck agents", async () => {
      const now = Date.now();
      const store = createStoreWithAgentForExec();
--- a/packages/engine/src/tests/scheduler-overlap-starvation.test.ts
+++ b/packages/engine/src/tests/scheduler-overlap-starvation.test.ts
@@ -1,6 +1,6 @@
 import { beforeEach, describe, expect, it, vi } from "vitest";
 import { Scheduler } from "../scheduler.js";
-import type { Task, TaskStore } from "@fusion/core";
+import type { Agent, AgentStore, Task, TaskStore } from "@fusion/core";

 function makeTask(overrides: Partial<Task> = {}): Task {
  return {
@@ -18,6 +18,23 @@ function makeTask(overrides: Partial<Task> = {}): Task {
  } as Task;
 }

+function createAgentStore(agents: Agent[]): AgentStore {
+  return {
+    listAgents: vi.fn(async (filter?: { state?: Agent["state"]; includeEphemeral?: boolean }) => {
+      return agents.filter((agent) => !filter?.state || agent.state === filter.state);
+    }),
+    getActiveHeartbeatRun: vi.fn(async () => null),
+    updateAgentState: vi.fn(async (agentId: string, state: Agent["state"]) => {
+      const agent = agents.find((candidate) => candidate.id === agentId);
+      if (agent) agent.state = state;
+    }),
+    syncExecutionTaskLink: vi.fn(async (agentId: string, taskId?: string) => {
+      const agent = agents.find((candidate) => candidate.id === agentId);
+      if (agent) agent.taskId = taskId;
+    }),
+  } as unknown as AgentStore;
+}
+
 function createStore(tasks: Task[], scopes: Record<string, string[]>): TaskStore {
  const updateTask = vi.fn(async (id: string, patch: Partial<Task>) => {
    const task = tasks.find((candidate) => candidate.id === id);
@@ -149,6 +166,55 @@ describe("scheduler overlap starvation regression (FN-057)", () => {
    expect(store.moveTask).toHaveBeenCalledWith("FN-031", "in-progress", expect.objectContaining({ allocateWorktree: expect.any(Function) }));
  });

+  it("FN-6954: clears stale running durable agents when overlap requeue parks todo task", async () => {
+    const tasks = [
+      makeTask({ id: "FN-6827", column: "in-progress", priority: "normal" }),
+      makeTask({ id: "FN-6709", column: "todo", priority: "urgent" }),
+    ];
+    const agents = [{ id: "agent-backend", state: "running", taskId: "FN-6709" } as Agent];
+    const agentStore = createAgentStore(agents);
+    const store = createStore(tasks, {
+      "FN-6827": ["packages/engine/src/scheduler.ts"],
+      "FN-6709": ["packages/engine/src/scheduler.ts"],
+    });
+
+    const scheduler = new Scheduler(store, { agentStore, hasActiveAgentExecution: () => false });
+    (scheduler as any).running = true;
+    await scheduler.schedule();
+
+    expect(store.updateTask).toHaveBeenCalledWith("FN-6709", {
+      status: "queued",
+      blockedBy: null,
+      overlapBlockedBy: "FN-6827",
+    });
+    expect(agents[0]).toMatchObject({ state: "active", taskId: undefined });
+    expect((agentStore as any).updateAgentState).toHaveBeenCalledWith("agent-backend", "active");
+    expect((agentStore as any).syncExecutionTaskLink).toHaveBeenCalledWith("agent-backend", undefined);
+    expect(tasks.find((task) => task.id === "FN-6709")).toMatchObject({ status: "queued", overlapBlockedBy: "FN-6827" });
+  });
+
+  it("FN-6954: preserves running durable agent when overlap requeue has live execution proof", async () => {
+    const tasks = [
+      makeTask({ id: "FN-6827", column: "in-progress", priority: "normal" }),
+      makeTask({ id: "FN-6709", column: "todo", priority: "urgent" }),
+    ];
+    const agents = [{ id: "agent-backend", state: "running", taskId: "FN-6709" } as Agent];
+    const agentStore = createAgentStore(agents);
+    const store = createStore(tasks, {
+      "FN-6827": ["packages/engine/src/scheduler.ts"],
+      "FN-6709": ["packages/engine/src/scheduler.ts"],
+    });
+
+    const scheduler = new Scheduler(store, { agentStore, hasActiveAgentExecution: (agentId) => agentId === "agent-backend" });
+    (scheduler as any).running = true;
+    await scheduler.schedule();
+
+    expect((agentStore as any).updateAgentState).not.toHaveBeenCalled();
+    expect((agentStore as any).syncExecutionTaskLink).not.toHaveBeenCalled();
+    expect(agents[0]).toMatchObject({ state: "running", taskId: "FN-6709" });
+    expect(tasks.find((task) => task.id === "FN-6709")).toMatchObject({ status: "queued", overlapBlockedBy: "FN-6827" });
+  });
+
  it("does not defer FN-078-style ready work behind non-runnable queued overlaps", async () => {
    const tasks = [
      makeTask({ id: "FN-069", column: "todo", status: "queued", priority: "high" }),
--- a/packages/engine/src/tests/self-healing-agent-link-drift.test.ts
+++ b/packages/engine/src/tests/self-healing-agent-link-drift.test.ts
@@ -12,6 +12,7 @@ describe("FN-4296: self-healing agent link drift", () => {
  function buildManager(agents: Agent[], tasks: Record<string, Task | null>, hasActiveAgentExecution?: (agentId: string) => boolean) {
    const store = {
      getTask: vi.fn(async (taskId: string) => tasks[taskId] ?? null),
+      recordRunAuditEvent: vi.fn(async () => {}),
    } as any;

    const agentStore = {
@@ -22,6 +23,10 @@ describe("FN-4296: self-healing agent link drift", () => {
        return agents;
      }),
      getActiveHeartbeatRun: vi.fn(async () => null),
+      updateAgentState: vi.fn(async (agentId: string, state: Agent["state"]) => {
+        const agent = agents.find((candidate) => candidate.id === agentId);
+        if (agent) agent.state = state;
+      }),
      syncExecutionTaskLink: vi.fn(async (agentId: string, taskId?: string) => {
        const agent = agents.find((candidate) => candidate.id === agentId);
        if (agent) agent.taskId = taskId;
@@ -29,7 +34,7 @@ describe("FN-4296: self-healing agent link drift", () => {
    } as unknown as AgentStore;

    const manager = new SelfHealingManager(store, { rootDir: "/tmp/test-project", agentStore, hasActiveAgentExecution });
-    return { manager, agentStore };
+    return { manager, agentStore, store };
  }

  it("FN-4296: durable agent linked to done task is cleared by sweep", async () => {
@@ -56,6 +61,96 @@ describe("FN-4296: self-healing agent link drift", () => {
    manager.stop();
  });

+  it("FN-6954: running durable agent on dependency-only queued todo is made active and unlinked", async () => {
+    const agents = [makeAgent("agent-backend", "FN-7000", "running")];
+    const queuedTask = {
+      id: "FN-7000",
+      column: "todo",
+      status: "queued",
+      blockedBy: "FN-6999",
+      overlapBlockedBy: null,
+    } as Task;
+    const { manager } = buildManager(agents, { "FN-7000": queuedTask }, () => false);
+
+    await manager.recoverDriftedAgentTaskLinks();
+
+    expect(agents[0]).toMatchObject({ state: "active", taskId: undefined });
+    expect(queuedTask).toMatchObject({ status: "queued", blockedBy: "FN-6999", overlapBlockedBy: null });
+    manager.stop();
+  });
+
+  it("FN-6954: running durable agent on overlap-queued triage task is made active and unlinked", async () => {
+    const agents = [makeAgent("agent-backend", "FN-7001", "running")];
+    const queuedTask = {
+      id: "FN-7001",
+      column: "triage",
+      status: "queued",
+      overlapBlockedBy: "FN-6827",
+    } as Task;
+    const { manager } = buildManager(agents, { "FN-7001": queuedTask }, () => false);
+
+    await manager.recoverDriftedAgentTaskLinks();
+
+    expect(agents[0]).toMatchObject({ state: "active", taskId: undefined });
+    expect(queuedTask).toMatchObject({ status: "queued", overlapBlockedBy: "FN-6827" });
+    manager.stop();
+  });
+
+  it("FN-6954: duplicate durable agents linked to one parked task preserve only live proof", async () => {
+    const agents = [
+      makeAgent("agent-stale", "FN-7002", "running"),
+      makeAgent("agent-live", "FN-7002", "running"),
+    ];
+    const queuedTask = { id: "FN-7002", column: "todo", status: "queued", overlapBlockedBy: "FN-6827" } as Task;
+    const { manager } = buildManager(agents, { "FN-7002": queuedTask }, (agentId) => agentId === "agent-live");
+
+    await manager.recoverDriftedAgentTaskLinks();
+
+    expect(agents[0]).toMatchObject({ state: "active", taskId: undefined });
+    expect(agents[1]).toMatchObject({ state: "running", taskId: "FN-7002" });
+    expect(queuedTask).toMatchObject({ status: "queued", overlapBlockedBy: "FN-6827" });
+    manager.stop();
+  });
+
+  it("FN-6954: running durable agent on lease-queued todo is made active and audited without clearing the lease", async () => {
+    const agents = [makeAgent("agent-backend", "FN-6709", "running")];
+    const queuedTask = {
+      id: "FN-6709",
+      column: "todo",
+      status: "queued",
+      overlapBlockedBy: "FN-6827",
+      blockedBy: null,
+    } as Task;
+    const blockerTask = { id: "FN-6827", column: "in-progress", assignedAgentId: "agent-other" } as Task;
+    const { manager, agentStore, store } = buildManager(
+      agents,
+      { "FN-6709": queuedTask, "FN-6827": blockerTask },
+      () => false,
+    );
+
+    await manager.recoverDriftedAgentTaskLinks();
+
+    expect(agents[0]).toMatchObject({ state: "active", taskId: undefined });
+    expect(queuedTask).toMatchObject({ status: "queued", overlapBlockedBy: "FN-6827" });
+    expect((agentStore as any).updateAgentState).toHaveBeenCalledWith("agent-backend", "active");
+    expect(store.recordRunAuditEvent).toHaveBeenCalledWith(expect.objectContaining({
+      mutationType: "task:reconcile-stale-agent-assignment",
+      target: "agent-backend",
+      metadata: expect.objectContaining({
+        agentId: "agent-backend",
+        taskId: "FN-6709",
+        taskColumn: "todo",
+        agentState: "running",
+        status: "queued",
+        overlapBlockedBy: "FN-6827",
+        hadFreshRun: false,
+        hadActiveExecution: false,
+        reason: expect.stringContaining("without fresh run or active execution"),
+      }),
+    }));
+    manager.stop();
+  });
+
  it("FN-4296: durable agent linked to todo task with fresh active run is NOT cleared", async () => {
    const agents = [makeAgent("agent-1", "FN-1")];
    const { manager, agentStore } = buildManager(agents, { "FN-1": { id: "FN-1", column: "todo" } as Task }, () => true);
--- a/packages/engine/src/tests/task-agent-sync.test.ts
+++ b/packages/engine/src/tests/task-agent-sync.test.ts
@@ -3,7 +3,7 @@ import { mkdtempSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";

-import { AgentStore, type AgentCreateInput, type Task } from "@fusion/core";
+import { AgentStore, type Agent, type AgentCreateInput, type Task } from "@fusion/core";
 import { describe, expect, it, vi } from "vitest";

 import { attachAgentLinkSync } from "../task-agent-sync.js";
@@ -20,11 +20,17 @@ class EventedStore extends EventEmitter {
 const createInput: AgentCreateInput = { name: "durable-agent", role: "executor" };

 describe("FN-4296: task agent sync", () => {
-  const runCase = async (to: string, hasActiveAgentExecution = false) => {
+  const runCase = async (to: string, hasActiveAgentExecution = false, agentState: Agent["state"] = "active") => {
    const store = new EventedStore();
+    const agents = [{ id: "agent-1", taskId: "FN-1", state: agentState }];
    const agentStore = {
-      listAgents: vi.fn(async () => [{ id: "agent-1", taskId: "FN-1" }]),
-      syncExecutionTaskLink: vi.fn(async () => undefined),
+      listAgents: vi.fn(async () => agents),
+      updateAgentState: vi.fn(async (_agentId: string, state: Agent["state"]) => {
+        agents[0].state = state;
+      }),
+      syncExecutionTaskLink: vi.fn(async (_agentId: string, taskId?: string) => {
+        agents[0].taskId = taskId;
+      }),
      assignTask: vi.fn(async () => undefined),
    } as any;

@@ -39,7 +45,7 @@ describe("FN-4296: task agent sync", () => {
    await Promise.resolve();
    await Promise.resolve();

-    return { detach, agentStore };
+    return { detach, agentStore, agents };
  };

  it("FN-4296: task:moved → done clears linked durable agent's taskId", async () => {
@@ -57,8 +63,16 @@ describe("FN-4296: task agent sync", () => {
    expect(agentStore.syncExecutionTaskLink).toHaveBeenCalledWith("agent-1", undefined);
  });

+  it("FN-6954: task:moved in-progress → todo queued by overlap clears stale running state", async () => {
+    const { agentStore, agents } = await runCase("todo", false, "running");
+    expect(agentStore.updateAgentState).toHaveBeenCalledWith("agent-1", "active");
+    expect(agentStore.syncExecutionTaskLink).toHaveBeenCalledWith("agent-1", undefined);
+    expect(agents[0]).toMatchObject({ state: "active", taskId: undefined });
+  });
+
  it("FN-4296: task:moved → todo does NOT clear link when hasActiveAgentExecution=true", async () => {
-    const { agentStore } = await runCase("todo", true);
+    const { agentStore } = await runCase("todo", true, "running");
+    expect(agentStore.updateAgentState).not.toHaveBeenCalled();
    expect(agentStore.syncExecutionTaskLink).not.toHaveBeenCalled();
  });

@@ -67,6 +81,13 @@ describe("FN-4296: task agent sync", () => {
    expect(agentStore.syncExecutionTaskLink).toHaveBeenCalledWith("agent-1", undefined);
  });

+  it("FN-6954: task:moved → triage queued behind overlap clears stale running link", async () => {
+    const { agentStore, agents } = await runCase("triage", false, "running");
+    expect(agentStore.updateAgentState).toHaveBeenCalledWith("agent-1", "active");
+    expect(agentStore.syncExecutionTaskLink).toHaveBeenCalledWith("agent-1", undefined);
+    expect(agents[0]).toMatchObject({ state: "active", taskId: undefined });
+  });
+
  it("FN-4296: task:moved → in-review does NOT clear link", async () => {
    const { agentStore } = await runCase("in-review", false);
    expect(agentStore.syncExecutionTaskLink).not.toHaveBeenCalled();
--- a/packages/engine/src/agent-heartbeat.ts
+++ b/packages/engine/src/agent-heartbeat.ts
@@ -35,7 +35,7 @@ import { buildPromptLayers, collapsePromptLayers } from "./prompt-layers.js";
 import { resolveAndEmitGoalContext } from "./goal-injection-diagnostics.js";
 import { createLogger, heartbeatLog, formatError } from "./logger.js";
 import { acquireTaskWorktree } from "./worktree-acquisition.js";
-import { createRunAuditor, type EngineRunContext } from "./run-audit.js";
+import { createRunAuditor, generateSyntheticRunId, type DatabaseMutationType, type EngineRunContext } from "./run-audit.js";
 import { promptWithFallback } from "./pi.js";
 import { createResolvedAgentSession, extractRuntimeHint, resolveHeartbeatSessionModels } from "./agent-session-helpers.js";
 import type { AgentActionGateContext } from "./agent-action-gate.js";
@@ -44,6 +44,7 @@ import type { AgentReflectionService } from "./agent-reflection.js";
 import { trimPromptMd, trimTaskDescription, trimTriggeringComments } from "./heartbeat-prompt-trim.js";
 import { detectDeicticReference, extractAntecedentCandidates, renderAmbiguityPromptBlock, scoreReferentConfidence } from "./room-ambiguity.js";
 import { countActiveAgentMembers, decideRoomCoordination, detectTaskFilingIntent, renderRoomCoordinationPromptBlock } from "./room-coordination.js";
+import { evaluateParkedAgentTaskLink, isParkedTaskColumn, type AgentTaskLinkExecutionProof } from "./task-agent-sync.js";

 const promptSizeLog = createLogger("prompt-size");

@@ -1256,6 +1257,45 @@ export class HeartbeatMonitor {
    }, this.pollIntervalMs);
  }

+  private async emitStaleAgentAssignmentAudit(options: {
+    agent: Pick<Agent, "id" | "state">;
+    taskId: string;
+    linkedTask: TaskDetail | null;
+    hadFreshRun: boolean;
+    hadActiveExecution: boolean;
+    reason: string;
+  }): Promise<void> {
+    if (!this.taskStore) return;
+    try {
+      await createRunAuditor(this.taskStore, {
+        runId: generateSyntheticRunId("heartbeat-stale-agent-assignment", options.taskId),
+        agentId: "heartbeat-monitor",
+        taskId: options.taskId,
+        taskLineageId: options.linkedTask?.lineageId,
+        phase: "reconcile-stale-agent-assignment",
+      }).database({
+        type: "task:reconcile-stale-agent-assignment" as DatabaseMutationType,
+        target: options.agent.id,
+        metadata: {
+          agentId: options.agent.id,
+          taskId: options.taskId,
+          taskColumn: options.linkedTask?.column ?? null,
+          agentState: options.agent.state,
+          status: options.linkedTask?.status ?? null,
+          blockedBy: options.linkedTask?.blockedBy ?? null,
+          overlapBlockedBy: options.linkedTask?.overlapBlockedBy ?? null,
+          hadFreshRun: options.hadFreshRun,
+          hadActiveExecution: options.hadActiveExecution,
+          reason: options.reason,
+        },
+      });
+    } catch (error) {
+      heartbeatLog.warn(
+        `Failed to emit stale agent assignment audit for ${options.agent.id}/${options.taskId}: ${error instanceof Error ? error.message : String(error)}`,
+      );
+    }
+  }
+
  /**
   * Find agents in `state="running"` that are not actually running and flip
   * them to `"active"`. An agent is considered orphaned when either:
@@ -1273,8 +1313,8 @@ export class HeartbeatMonitor {
   * logged but do not block the caller.
   *
   * Complements SelfHealingManager.recoverAgentsRunningOnInactiveTasks():
-   * heartbeat reconciliation handles stale/no-run conditions, while self-healing
-   * handles task-column mismatches (for example running agents linked to todo tasks).
+   * heartbeat reconciliation handles stale/no-run conditions and the prompt-critical
+   * parked todo/triage assignment drift before Reports Health Check renders.
   */
  private async reconcileOrphanedRunningAgents(): Promise<void> {
    try {
@@ -1282,10 +1322,33 @@ export class HeartbeatMonitor {
      const now = Date.now();
      for (const agent of runningAgents) {
        let reason: string | null = null;
+        let clearTaskLink = false;
+        let taskIdToClear: string | null = null;
+        let parkedProof: AgentTaskLinkExecutionProof | null = null;
+        let linkedTask: TaskDetail | null = null;
        const activeRun = await this.store.getActiveHeartbeatRun(agent.id);
-        if (!activeRun) {
+        if (!isEphemeralAgent(agent) && agent.taskId && this.taskStore) {
+          linkedTask = await this.taskStore.getTask(agent.taskId);
+          parkedProof = evaluateParkedAgentTaskLink({
+            agent,
+            linkedTask,
+            activeRun,
+            hasActiveAgentExecution: (agentId) => this.trackedAgents.has(agentId),
+            now,
+          });
+          /*
+          FNXC:AgentTaskStateDrift 2026-06-23-09:02:
+          Reports Health Check must not render a durable direct report as running a parked todo/triage task unless a fresh heartbeat run or tracked executor signal proves live execution. Clearing Agent.taskId here preserves overlapBlockedBy on the task row; the file-scope lease remains the scheduler's source of truth.
+          */
+          if (isParkedTaskColumn(linkedTask) && !parkedProof.shouldPreserveParkedLink) {
+            reason = `parked ${linkedTask.column} task ${agent.taskId} without live execution proof`;
+            clearTaskLink = true;
+            taskIdToClear = agent.taskId;
+          }
+        }
+        if (!reason && !activeRun) {
          reason = "no active run";
-        } else if (!this.trackedAgents.has(agent.id)) {
+        } else if (!reason && activeRun && !this.trackedAgents.has(agent.id)) {
          const timeoutMs = this.resolveAgentConfig(agent.id).heartbeatTimeoutMs;
          const heartbeatAgeMs = getHeartbeatAgeMs(agent, now);
          // NOTE(FN-4278): this stale gate intentionally uses a per-run work-budget
@@ -1311,9 +1374,21 @@ export class HeartbeatMonitor {
        }
        if (!reason) continue;
        try {
+          const staleAgentState = agent.state;
          await this.store.updateAgentState(agent.id, "active");
+          if (clearTaskLink) {
+            await this.store.syncExecutionTaskLink(agent.id, undefined);
+            await this.emitStaleAgentAssignmentAudit({
+              agent: { id: agent.id, state: staleAgentState },
+              taskId: taskIdToClear!,
+              linkedTask,
+              hadFreshRun: parkedProof?.hasFreshRun ?? false,
+              hadActiveExecution: parkedProof?.hasActiveExecution ?? false,
+              reason,
+            });
+          }
          this.clearRunState(agent.id);
-          heartbeatLog.log(`Reconciled orphaned running agent ${agent.id} → active (${reason})`);
+          heartbeatLog.log(`Reconciled orphaned running agent ${agent.id} → active (${reason})${clearTaskLink ? "; stale task link cleared" : ""}`);
        } catch (err) {
          heartbeatLog.warn(`Failed to reconcile orphaned running agent ${agent.id}: ${err instanceof Error ? err.message : String(err)}`);
        }
@@ -3234,8 +3309,36 @@ export class HeartbeatMonitor {
      const lastHeartbeatTs = report.lastHeartbeatAt ? Date.parse(report.lastHeartbeatAt) : NaN;
      const heartbeatAgeMs = Number.isFinite(lastHeartbeatTs) ? Math.max(0, now - lastHeartbeatTs) : Infinity;

+      let renderedState = report.state;
+      let renderedTask = report.taskId ?? "—";
+      let staleParkedAssignment = false;
+      if (report.state === "running" && !isEphemeralAgent(report) && report.taskId && this.taskStore) {
+        try {
+          const linkedTask = await this.taskStore.getTask(report.taskId);
+          if (isParkedTaskColumn(linkedTask)) {
+            const activeRun = await agentStore.getActiveHeartbeatRun(report.id);
+            const proof = evaluateParkedAgentTaskLink({
+              agent: report,
+              linkedTask,
+              activeRun,
+              hasActiveAgentExecution: (candidateId) => this.trackedAgents.has(candidateId),
+              now,
+            });
+            if (!proof.shouldPreserveParkedLink) {
+              staleParkedAssignment = true;
+              renderedState = "active";
+              renderedTask = `${report.taskId} (queued/no live run)`;
+            }
+          }
+        } catch (error) {
+          heartbeatLog.warn(`[reports-health] failed to validate task link for ${report.id}/${report.taskId}: ${error instanceof Error ? error.message : String(error)}`);
+        }
+      }
+
      let health = "healthy";
-      if (report.state === "paused") {
+      if (staleParkedAssignment) {
+        health = "**stale** assignment";
+      } else if (report.state === "paused") {
        health = report.pauseReason ? `paused (${report.pauseReason})` : "paused";
      } else if (report.state === "error") {
        health = "**stuck**";
@@ -3246,8 +3349,8 @@ export class HeartbeatMonitor {
        heartbeatLog.log(`[reports-health] stale report ${report.id} intervalSource=${intervalSource} staleThresholdMs=${staleThresholdMs} heartbeatAgeMs=${heartbeatAgeMs}`);
      }

-      const task = report.taskId ?? "—";
-      const state = report.state;
+      const task = renderedTask;
+      const state = renderedState;
      const heartbeat = formatRelativeTime(report.lastHeartbeatAt);
      return `| ${report.name} | ${state} | ${task} | ${heartbeat} | ${health} |`;
    }));
--- a/packages/engine/src/run-audit.ts
+++ b/packages/engine/src/run-audit.ts
@@ -515,6 +515,11 @@ export type DatabaseMutationType =
  | "task:resume-limbo-escalated"
  /** Metadata: { taskId, executionAgeMs, graceMs, staleBindingAgeFloorMs, checkedOutBy, agentPresent, lastActivityMs, hasRecentRunAudit, worktree, branch, worktreeExists, signalReason } */
  | "task:reclaim-phantom-executor-binding"
+  /**
+   * FNXC:AgentTaskStateDrift 2026-06-23-08:50:
+   * Self-healing must leave file-scope lease queues intact while recording when stale durable Agent.taskId/state drift is cleared. Metadata: { agentId, taskId, taskColumn, agentState, status, blockedBy, overlapBlockedBy, hadFreshRun, hadActiveExecution, reason }.
+   */
+  | "task:reconcile-stale-agent-assignment"
  /** Metadata: { taskId, branch, worktree, checkedOutBy, executionStartedAt, executionAgeMs, graceMs, liveWorktreeBoundBranch, reason } */
  | "task:reclaim-self-owned-branch-conflict-no-action"
  | "task:orphan-detected-no-action"
--- a/packages/engine/src/runtimes/in-process-runtime.ts
+++ b/packages/engine/src/runtimes/in-process-runtime.ts
@@ -375,6 +375,7 @@ export class InProcessRuntime
        maxWorktrees: this.config.maxWorktrees,
        semaphore: this.globalSemaphore,
        agentStore: this.agentStore,
+        hasActiveAgentExecution: (agentId: string) => this.heartbeatMonitor?.getTrackedAgents().includes(agentId) ?? false,
        missionStore,
        missionAutopilot,
        missionExecutionLoop,
--- a/packages/engine/src/scheduler.ts
+++ b/packages/engine/src/scheduler.ts
@@ -36,6 +36,7 @@ import { UnlinkedMissionsAdvisoryReporter } from "./unlinked-missions-advisory-r
 import { createRunAuditor, generateSyntheticRunId } from "./run-audit.js";
 import { isWorkflowColumnsEnabled, DEFAULT_WORKFLOW_POOL_ID } from "@fusion/core";
 import { runHoldReleaseSweep, type SlotReservation } from "./hold-release.js";
+import { evaluateParkedAgentTaskLink } from "./task-agent-sync.js";

 function shouldRunWorkflowColumnScheduler(_settings: Settings): boolean {
  /*
@@ -446,6 +447,8 @@ export interface SchedulerOptions {
  semaphore?: AgentSemaphore;
  /** Optional AgentStore for durable-agent state rollback during overlap requeue. */
  agentStore?: AgentStore;
+  /** Optional live executor signal that preserves parked durable-agent links while work is truly active. */
+  hasActiveAgentExecution?: (agentId: string) => boolean;
  /** Called when scheduler starts a task */
  onSchedule?: (task: Task) => void;
  /** Called when a task is blocked by deps */
@@ -1068,13 +1071,29 @@ export class Scheduler {
    const agentStore = this.options.agentStore;
    if (!agentStore) return;

-    const runningAgents = await agentStore.listAgents({ state: "running", includeEphemeral: true });
+    const runningAgents = await agentStore.listAgents({ state: "running", includeEphemeral: false });
    const linkedAgents = runningAgents.filter((agent) => agent.taskId === taskId);

    for (const agent of linkedAgents) {
+      const activeRun = await agentStore.getActiveHeartbeatRun?.(agent.id);
+      const proof = evaluateParkedAgentTaskLink({
+        agent,
+        linkedTask: { column: "todo" } as Pick<Task, "column">,
+        activeRun,
+        hasActiveAgentExecution: this.options.hasActiveAgentExecution,
+      });
+      if (proof.shouldPreserveParkedLink) {
+        schedulerLog.log(
+          `Preserved running agent ${agent.id} for queued ${taskId}; live proof freshRun=${proof.hasFreshRun} activeExecution=${proof.hasActiveExecution}`,
+        );
+        continue;
+      }
+
      await agentStore.updateAgentState(agent.id, "active");
      await agentStore.syncExecutionTaskLink(agent.id, undefined);
-      schedulerLog.log(`Rolled back running agent ${agent.id} after overlap requeue of ${taskId}`);
+      schedulerLog.log(
+        `Cleared stale running agent ${agent.id} after overlap requeue of ${taskId}; file-scope lease remains queued`,
+      );
    }
  }

@@ -2513,6 +2532,7 @@ export class Scheduler {
                  blockedBy: null,
                  overlapBlockedBy: overlappingTaskId,
                });
+                await this.rollbackRunningAgentsForQueuedTodoTask(task.id);
                await this.logDispatchQueuedReason(
                  task.id,
                  `queued — blocked by active file-scope lease ${overlappingTaskId} (column=${activeLeaseColumn})`,
--- a/packages/engine/src/self-healing.ts
+++ b/packages/engine/src/self-healing.ts
@@ -30,7 +30,7 @@ import { setImmediate as setImmediateCb } from "node:timers";
 import { existsSync, mkdirSync, readdirSync, readFileSync, realpathSync, rmSync, statSync, writeFileSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { isAbsolute, join, relative, resolve } from "node:path";
-import { IN_REVIEW_STALL_DEADLOCK_LOG_PREFIX, IN_REVIEW_STALL_LOG_PREFIX, IN_REVIEW_STALL_TERMINAL_LOG_PREFIX, allowsAutoMergeProcessing, countRecentIdenticalStallEntries, detectDependencyCycle, detectSelfDefeatingDependency, evaluateNoCommitsNoOpFinalize, getInReviewStalledSignal, getInReviewStallReason, getPrimaryPrInfo, getStalePausedReviewSignal, getStalePausedTodoSignal, getTaskHardMergeBlocker, getTaskMergeBlocker, isEphemeralAgent, isMergeRequestContractShadowEnabled, isWorkflowColumnsEnabled, isSharedBranchGroupMemberIntegration, parseExplicitDuplicateMarker, resolveMaxAutoMergeRetries, type AgentStore, type ChatStore, type MessageStore, type TaskStore, type Settings, type Task, type MergeDetails, type TaskPriority, type MergeResult } from "@fusion/core";
+import { IN_REVIEW_STALL_DEADLOCK_LOG_PREFIX, IN_REVIEW_STALL_LOG_PREFIX, IN_REVIEW_STALL_TERMINAL_LOG_PREFIX, allowsAutoMergeProcessing, countRecentIdenticalStallEntries, detectDependencyCycle, detectSelfDefeatingDependency, evaluateNoCommitsNoOpFinalize, getInReviewStalledSignal, getInReviewStallReason, getPrimaryPrInfo, getStalePausedReviewSignal, getStalePausedTodoSignal, getTaskHardMergeBlocker, getTaskMergeBlocker, isEphemeralAgent, isMergeRequestContractShadowEnabled, isWorkflowColumnsEnabled, isSharedBranchGroupMemberIntegration, parseExplicitDuplicateMarker, resolveMaxAutoMergeRetries, type Agent, type AgentStore, type ChatStore, type MessageStore, type TaskStore, type Settings, type Task, type MergeDetails, type TaskPriority, type MergeResult } from "@fusion/core";
 import type { MeshLeaseManager } from "./mesh-lease-manager.js";
 import { createLogger, schedulerLog } from "./logger.js";
 import { mergeEffectiveSettings } from "./effective-settings.js";
@@ -67,6 +67,7 @@ import {
 import type { GhostBugDecision } from "./triage-preflight.js";
 import { DependencyBlockedTodoReporter } from "./dependency-blocked-todo-reporter.js";
 import { filterPathsByIgnoreList, getUnmetSchedulingDependencies, isCoordinationOnlyTask, pathsOverlap } from "./scheduler.js";
+import { evaluateParkedAgentTaskLink, PARKED_AGENT_LINK_FRESH_RUN_MS } from "./task-agent-sync.js";

 const log = createLogger("self-healing");
 const worktreeMetadataReconcileLog = createLogger("worktree-metadata-reconcile");
@@ -451,7 +452,7 @@ const DEFAULT_UNBACKED_MERGING_FANOUT_GRACE_MS = 60_000;
 const DURABLE_ERROR_RECOVERY_MAX_RETRIES = 5;
 const DURABLE_ERROR_RECOVERY_BASE_COOLDOWN_MS = 30_000;
 const DURABLE_ERROR_RECOVERY_MAX_COOLDOWN_MS = 15 * 60_000;
-const RUNNING_ON_INACTIVE_TASK_STALE_RUN_MS = 5 * 60_000;
+const RUNNING_ON_INACTIVE_TASK_STALE_RUN_MS = PARKED_AGENT_LINK_FRESH_RUN_MS;

 function bumpTaskPriority(priority: TaskPriority | undefined): TaskPriority {
  switch (priority ?? "normal") {
@@ -8744,6 +8745,44 @@ export class SelfHealingManager {
    return Math.min(exponential, DURABLE_ERROR_RECOVERY_MAX_COOLDOWN_MS);
  }

+  private async emitStaleAgentAssignmentAudit(options: {
+    agent: Pick<Agent, "id" | "state">;
+    taskId: string;
+    linkedTask?: Task | null;
+    hadFreshRun: boolean;
+    hadActiveExecution: boolean;
+    reason: string;
+  }): Promise<void> {
+    try {
+      await createRunAuditor(this.store, {
+        runId: generateSyntheticRunId("self-healing-stale-agent-assignment", options.taskId),
+        agentId: "self-healing",
+        taskId: options.taskId,
+        taskLineageId: options.linkedTask?.lineageId,
+        phase: "reconcile-stale-agent-assignment",
+      }).database({
+        type: "task:reconcile-stale-agent-assignment" as DatabaseMutationType,
+        target: options.agent.id,
+        metadata: {
+          agentId: options.agent.id,
+          taskId: options.taskId,
+          taskColumn: options.linkedTask?.column ?? null,
+          agentState: options.agent.state,
+          status: options.linkedTask?.status ?? null,
+          blockedBy: options.linkedTask?.blockedBy ?? null,
+          overlapBlockedBy: options.linkedTask?.overlapBlockedBy ?? null,
+          hadFreshRun: options.hadFreshRun,
+          hadActiveExecution: options.hadActiveExecution,
+          reason: options.reason,
+        },
+      });
+    } catch (error) {
+      log.warn(
+        `Failed to emit stale agent assignment audit for ${options.agent.id}/${options.taskId}: ${error instanceof Error ? error.message : String(error)}`,
+      );
+    }
+  }
+
  async recoverAgentsRunningOnInactiveTasks(): Promise<number> {
    const agentStore = this.options.agentStore;
    if (!agentStore) {
@@ -8765,17 +8804,33 @@ export class SelfHealingManager {
      }

      const activeRun = await agentStore.getActiveHeartbeatRun(agent.id);
-      const runStartedAt = activeRun?.startedAt;
-      const runAgeMs = runStartedAt ? now - Date.parse(runStartedAt) : Number.POSITIVE_INFINITY;
-      const hasFreshRun = Boolean(activeRun) && Number.isFinite(runAgeMs) && runAgeMs <= RUNNING_ON_INACTIVE_TASK_STALE_RUN_MS;
-      if (hasFreshRun || this.options.hasActiveAgentExecution?.(agent.id) === true) {
+      const proof = evaluateParkedAgentTaskLink({
+        agent,
+        linkedTask: linkedTask ?? { column: "todo" } as Pick<Task, "column">,
+        activeRun,
+        hasActiveAgentExecution: this.options.hasActiveAgentExecution,
+        now,
+      });
+      if (proof.hasFreshRun || proof.hasActiveExecution) {
        continue;
      }

+      const reason = linkedTask
+        ? `running durable agent linked to inactive ${linkedTask.column} task without live execution proof`
+        : "running durable agent linked to missing task without live execution proof";
+      const staleAgentState = agent.state;
      await agentStore.updateAgentState(agent.id, "active");
      await agentStore.syncExecutionTaskLink(agent.id, undefined);
+      await this.emitStaleAgentAssignmentAudit({
+        agent: { id: agent.id, state: staleAgentState },
+        taskId: agent.taskId,
+        linkedTask,
+        hadFreshRun: proof.hasFreshRun,
+        hadActiveExecution: proof.hasActiveExecution,
+        reason,
+      });
      recoveredAgentIds.add(agent.id);
-      log.log(`Recovered running durable agent ${agent.id} on inactive task ${agent.taskId}`);
+      log.log(`Recovered running durable agent ${agent.id} on inactive task ${agent.taskId}; file-scope lease preserved when present`);
    }

    return recoveredAgentIds.size;
@@ -8800,6 +8855,8 @@ export class SelfHealingManager {
      const linkedTask = await this.store.getTask(linkedTaskId);
      let shouldClear = false;
      let reason = "";
+      let hadFreshRun = false;
+      let hadActiveExecution = false;

      if (!linkedTask) {
        shouldClear = true;
@@ -8812,13 +8869,18 @@ export class SelfHealingManager {
        reason = `linked task assigned to ${linkedTask.assignedAgentId}`;
      } else if (linkedTask.column === "todo" || linkedTask.column === "triage") {
        const activeRun = await agentStore.getActiveHeartbeatRun(agent.id);
-        const runStartedAt = activeRun?.startedAt;
-        const runAgeMs = runStartedAt ? now - Date.parse(runStartedAt) : Number.POSITIVE_INFINITY;
-        const hasFreshRun = Boolean(activeRun) && Number.isFinite(runAgeMs) && runAgeMs <= RUNNING_ON_INACTIVE_TASK_STALE_RUN_MS;
-        const hasActiveExecution = this.options.hasActiveAgentExecution?.(agent.id) === true;
-        if (!hasFreshRun && !hasActiveExecution) {
+        const proof = evaluateParkedAgentTaskLink({
+          agent,
+          linkedTask,
+          activeRun,
+          hasActiveAgentExecution: this.options.hasActiveAgentExecution,
+          now,
+        });
+        hadFreshRun = proof.hasFreshRun;
+        hadActiveExecution = proof.hasActiveExecution;
+        if (!proof.shouldPreserveParkedLink) {
          shouldClear = true;
-          reason = `linked task in queued column ${linkedTask.column} without fresh run`;
+          reason = `linked task in queued column ${linkedTask.column} without fresh run or active execution`;
        }
      }

@@ -8826,9 +8888,21 @@ export class SelfHealingManager {
        continue;
      }

+      const staleAgentState = agent.state;
+      if (agent.state === "running") {
+        await agentStore.updateAgentState(agent.id, "active");
+      }
      await agentStore.syncExecutionTaskLink(agent.id, undefined);
+      await this.emitStaleAgentAssignmentAudit({
+        agent: { id: agent.id, state: staleAgentState },
+        taskId: linkedTaskId,
+        linkedTask,
+        hadFreshRun,
+        hadActiveExecution,
+        reason,
+      });
      clearedAgentIds.add(agent.id);
-      log.log(`Cleared drifted durable agent task link for ${agent.id} (${linkedTaskId}): ${reason}`);
+      log.log(`Cleared drifted durable agent task link for ${agent.id} (${linkedTaskId}): ${reason}; file-scope lease preserved when present`);
    }

    log.log(`Recovered ${clearedAgentIds.size} drifted durable agent task link(s)`);
--- a/packages/engine/src/task-agent-sync.ts
+++ b/packages/engine/src/task-agent-sync.ts
@@ -1,4 +1,51 @@
-import type { AgentStore, TaskStore } from "@fusion/core";
+import type { Agent, AgentHeartbeatRun, AgentStore, Task, TaskStore } from "@fusion/core";
+
+export const PARKED_AGENT_LINK_FRESH_RUN_MS = 5 * 60_000;
+
+export interface AgentTaskLinkExecutionProof {
+  hasFreshRun: boolean;
+  hasActiveExecution: boolean;
+  shouldPreserveParkedLink: boolean;
+  runAgeMs: number;
+}
+
+export function hasFreshActiveHeartbeatRun(
+  activeRun: AgentHeartbeatRun | null | undefined,
+  now = Date.now(),
+  freshRunMs = PARKED_AGENT_LINK_FRESH_RUN_MS,
+): { hasFreshRun: boolean; runAgeMs: number } {
+  const runStartedAt = activeRun?.startedAt;
+  const runAgeMs = runStartedAt ? now - Date.parse(runStartedAt) : Number.POSITIVE_INFINITY;
+  return {
+    hasFreshRun: Boolean(activeRun) && Number.isFinite(runAgeMs) && runAgeMs <= freshRunMs,
+    runAgeMs,
+  };
+}
+
+export function isParkedTaskColumn(task: Pick<Task, "column"> | null | undefined): boolean {
+  return task?.column === "todo" || task?.column === "triage";
+}
+
+export function evaluateParkedAgentTaskLink(options: {
+  agent: Pick<Agent, "id" | "taskId">;
+  linkedTask: Pick<Task, "column"> | null | undefined;
+  activeRun?: AgentHeartbeatRun | null;
+  hasActiveAgentExecution?: (agentId: string) => boolean;
+  now?: number;
+}): AgentTaskLinkExecutionProof {
+  const { hasFreshRun, runAgeMs } = hasFreshActiveHeartbeatRun(options.activeRun, options.now);
+  const hasActiveExecution = options.hasActiveAgentExecution?.(options.agent.id) === true;
+  /*
+  FNXC:AgentTaskStateDrift 2026-06-23-08:33:
+  Agent.taskId is a running assignment for parked todo/triage tasks only when the agent has live execution proof: a fresh active heartbeat run or an executor-active signal. File-scope overlapBlockedBy keeps the task queued but never proves the blocked task itself is executing.
+  */
+  return {
+    hasFreshRun,
+    hasActiveExecution,
+    shouldPreserveParkedLink: isParkedTaskColumn(options.linkedTask) && (hasFreshRun || hasActiveExecution),
+    runAgeMs,
+  };
+}

 type LoggerLike = { log: (msg: string) => void; warn: (msg: string) => void };

@@ -24,10 +71,22 @@ export function attachAgentLinkSync(opts: AttachAgentLinkSyncOptions): () => voi
      const linkedAgents = agents.filter((agent) => agent.taskId === task.id);

      for (const agent of linkedAgents) {
-        if ((to === "todo" || to === "triage") && opts.hasActiveAgentExecution?.(agent.id) === true) {
-          continue;
+        if (to === "todo" || to === "triage") {
+          const activeRun = await opts.agentStore.getActiveHeartbeatRun?.(agent.id);
+          const proof = evaluateParkedAgentTaskLink({
+            agent,
+            linkedTask: { column: to } as Pick<Task, "column">,
+            activeRun,
+            hasActiveAgentExecution: opts.hasActiveAgentExecution,
+          });
+          if (proof.shouldPreserveParkedLink) {
+            continue;
+          }
        }

+        if (agent.state === "running") {
+          await opts.agentStore.updateAgentState(agent.id, "active");
+        }
        await opts.agentStore.syncExecutionTaskLink(agent.id, undefined);
        logger.log(`taskAgentLinkSync: cleared agent ${agent.id} taskId from ${task.id} after move ${from} → ${to}`);
      }