fix(engine): reap leaked fn-verify verification worktrees in the temp-dir sweep

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.changeset/fn-verify-worktree-reaping.md

@@ -0,0 +1,7 @@
+---
+"@runfusion/fusion": patch
+---
+
+summary: Leaked verification worktrees are now reaped, so planning no longer queues behind exhausted slots.
+category: fix
+dev: mission-verification's fn-verify-* checkouts leaked on process death (dispose is in-process best-effort); the self-healing temp-dir sweep now includes the fn-verify- prefix under tmpdir() with the same age gates and active-session refusal.

packages/engine/src/__tests__/self-healing-tempdir-sweep.test.ts

@@ -193,6 +193,28 @@ describe("SelfHealingManager worktrees-dir sweeps", () => {
 });
 
 describe("SelfHealingManager temp-dir AI merge worktree sweep", () => {
+  it("removes stale fn-verify verification checkouts from tmpdir (leak found on the live board)", async () => {
+    /*
+    FNXC:TempWorktreeSweep 2026-07-31-22:55:
+    GitCheckoutMaterializer's dispose() is in-process best-effort; a killed process leaks the
+    fn-verify-* checkout AND its git worktree registration forever, because no sweep knew the
+    prefix. Reverting the sweep-prefix change makes this test fail (the dir survives).
+    */
+    const stale = tempMergeDir(`fn-verify-${Math.random().toString(36).slice(2)}`);
+    makeStale(stale);
+    const staleApp = tempMergeDir(`fn-verify-app-${Math.random().toString(36).slice(2)}`);
+    makeStale(staleApp);
+    const fresh = tempMergeDir(`fn-verify-fresh-${Math.random().toString(36).slice(2)}`);
+    const { manager } = makeManager();
+
+    await expect(sweep(manager)).resolves.toBe(2);
+
+    expect(existsSync(stale)).toBe(false);
+    expect(existsSync(staleApp)).toBe(false);
+    // Young checkouts may belong to a live verification run — the age gate must hold.
+    expect(existsSync(fresh)).toBe(true);
+  });
+
   it("removes stale fusion-ai-merge directories and emits success audits", async () => {
     const stale = tempMergeDir();
     makeStale(stale);

packages/engine/src/self-healing.ts

@@ -14905,7 +14905,19 @@ const movedTask = await this.store.moveTask(task.id, completeLane);
       for (const tempRoot of roots) {
         let entries: string[];
         try {
-          entries = readdirSync(tempRoot).filter((entry) => entry.startsWith("fusion-ai-merge-"));
+          /*
+          FNXC:TempWorktreeSweep 2026-07-31-22:55:
+          `fn-verify-` (and `fn-verify-app-`) checkouts from mission-verification's
+          GitCheckoutMaterializer leak when the process dies between materialize and dispose — seven
+          registered worktrees aged Jul 24-27 were found holding registrations, and on the live board
+          the visible symptom was planning admission queueing behind exhausted worktree slots
+          ("queued to plan" for ~6 minutes). Their dispose() is best-effort in-process only; this
+          sweep is the only out-of-process reaper, so it must know the prefix. Verification checkouts
+          are detached throwaways that only ever live under tmpdir(), so the extra prefixes apply to
+          that root alone; the same age gates, active-session refusal, and audit rows govern them.
+          */
+          const sweepPrefixes = tempRoot === tmpdir() ? ["fusion-ai-merge-", "fn-verify-"] : ["fusion-ai-merge-"];
+          entries = readdirSync(tempRoot).filter((entry) => sweepPrefixes.some((prefix) => entry.startsWith(prefix)));
         } catch (err: unknown) {
           if (!existsSync(tempRoot)) continue;
           const errorMessage = err instanceof Error ? err.message : String(err);