feat(FN-5058): merge fusion/fn-5058

packages/engine/src/__tests__/worktree-admin-entry-prune.test.ts

@@ -0,0 +1,155 @@
+import { mkdtempSync, mkdirSync, rmSync, writeFileSync } from "node:fs";
+import { execSync } from "node:child_process";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+afterEach(() => {
+  vi.restoreAllMocks();
+  vi.resetModules();
+  vi.unmock("node:child_process");
+  vi.unmock("node:fs");
+  vi.unmock("../worktree-hooks.js");
+  vi.unmock("../worktree-prune.js");
+});
+
+describe("worktree prune wiring", () => {
+  it("step-session createStepWorktree pairs cleanup deletes with prune reasons", async () => {
+    const pruneSpy = vi.fn().mockResolvedValue(undefined);
+    const execMock = vi.fn();
+    (execMock as any)[Symbol.for("nodejs.util.promisify.custom")] = execMock;
+
+    execMock.mockRejectedValueOnce(new Error("create failed")).mockResolvedValueOnce({ stdout: "", stderr: "" });
+
+    vi.doMock("node:child_process", () => ({ exec: execMock }));
+    vi.doMock("../worktree-prune.js", async (importOriginal) => {
+      const actual = await importOriginal<typeof import("../worktree-prune.js")>();
+      return { ...actual, pruneWorktreeAdminEntries: pruneSpy };
+    });
+    vi.doMock("../worktree-hooks.js", () => ({
+      installTaskWorktreeIdentityGuard: vi.fn().mockRejectedValue(new Error("guard failed")),
+    }));
+
+    const { StepSessionExecutor } = await import("../step-session-executor.js");
+    const task = {
+      id: "FN-5058",
+      title: "t",
+      description: "d",
+      column: "in-progress",
+      dependencies: [],
+      steps: [],
+      currentStep: 0,
+      log: [],
+      prompt: "",
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    } as any;
+
+    const executor = new StepSessionExecutor({ taskDetail: task, worktreePath: "/repo", rootDir: "/repo", settings: {} as any });
+    await expect((executor as any).createStepWorktree(1)).rejects.toThrow("create failed");
+    expect(pruneSpy).toHaveBeenCalledWith(expect.objectContaining({ reason: "step-session-create-failed" }));
+
+    execMock.mockReset();
+    execMock.mockResolvedValueOnce({ stdout: "", stderr: "" }).mockResolvedValueOnce({ stdout: "", stderr: "" });
+    await expect((executor as any).createStepWorktree(2)).rejects.toThrow("guard failed");
+    expect(pruneSpy).toHaveBeenCalledWith(expect.objectContaining({ reason: "step-session-guard-failed" }));
+  });
+
+  it("step-session cleanup swallows prune helper rejection", async () => {
+    const pruneSpy = vi.fn().mockRejectedValue(new Error("prune boom"));
+    const execMock = vi.fn();
+    (execMock as any)[Symbol.for("nodejs.util.promisify.custom")] = execMock;
+    execMock.mockRejectedValueOnce(new Error("create failed")).mockResolvedValueOnce({ stdout: "", stderr: "" });
+
+    vi.doMock("node:child_process", () => ({ exec: execMock }));
+    vi.doMock("../worktree-prune.js", async (importOriginal) => {
+      const actual = await importOriginal<typeof import("../worktree-prune.js")>();
+      return { ...actual, pruneWorktreeAdminEntries: pruneSpy };
+    });
+    const { StepSessionExecutor } = await import("../step-session-executor.js");
+    const task = {
+      id: "FN-5058",
+      title: "t",
+      description: "d",
+      column: "in-progress",
+      dependencies: [],
+      steps: [],
+      currentStep: 0,
+      log: [],
+      prompt: "",
+      createdAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    } as any;
+
+    const executor = new StepSessionExecutor({ taskDetail: task, worktreePath: "/repo", rootDir: "/repo", settings: {} as any });
+    await expect((executor as any).createStepWorktree(3)).rejects.toThrow("create failed");
+  });
+
+  it("native backend create calls prune after guard cleanup", async () => {
+    const pruneSpy = vi.fn().mockResolvedValue(undefined);
+    const execMock = vi.fn();
+    (execMock as any)[Symbol.for("nodejs.util.promisify.custom")] = execMock;
+    execMock.mockResolvedValueOnce({ stdout: "", stderr: "" }).mockResolvedValueOnce({ stdout: "", stderr: "" });
+
+    vi.doMock("node:child_process", () => ({ exec: execMock }));
+    vi.doMock("../worktree-prune.js", async (importOriginal) => {
+      const actual = await importOriginal<typeof import("../worktree-prune.js")>();
+      return { ...actual, pruneWorktreeAdminEntries: pruneSpy };
+    });
+    vi.doMock("../worktree-hooks.js", () => ({
+      installTaskWorktreeIdentityGuard: vi.fn().mockRejectedValue(new Error("guard failed")),
+    }));
+
+    const { NativeWorktreeBackend } = await import("../worktree-backend.js");
+    await expect(
+      new NativeWorktreeBackend({ audit: { git: vi.fn() } as any }).create({
+        rootDir: "/repo",
+        worktreePath: "/repo/.worktrees/fn-5058",
+        branch: "fusion/fn-5058",
+        taskId: "FN-5058",
+      }),
+    ).rejects.toThrow("guard failed");
+
+    expect(pruneSpy).toHaveBeenCalledWith(expect.objectContaining({ reason: "backend-guard-failed" }));
+  });
+
+});
+
+describe("pruneWorktreeAdminEntries helper", () => {
+  it("swallows git prune failure and audits success=false metadata", async () => {
+    const execMock = vi.fn();
+    (execMock as any)[Symbol.for("nodejs.util.promisify.custom")] = execMock;
+    execMock.mockRejectedValue(new Error("boom"));
+    vi.doMock("node:child_process", async () => {
+      const actual = await vi.importActual<typeof import("node:child_process")>("node:child_process");
+      return { ...actual, exec: execMock };
+    });
+
+    vi.unmock("../worktree-prune.js");
+    const { pruneWorktreeAdminEntries } = await import("../worktree-prune.js");
+    const audit = vi.fn().mockResolvedValue(undefined);
+    await pruneWorktreeAdminEntries({ rootDir: "/repo", auditor: { git: audit }, reason: "test-failure", target: "/repo/.worktrees/x" });
+  });
+
+  it("runs git worktree prune end-to-end in a real repository", async () => {
+    vi.unmock("../worktree-prune.js");
+    const { pruneWorktreeAdminEntries } = await import("../worktree-prune.js");
+    const root = mkdtempSync(join(tmpdir(), "fn-5058-prune-"));
+    const repo = join(root, "repo");
+    const wt = join(root, "repo-wt");
+    mkdirSync(repo, { recursive: true });
+
+    execSync("git init", { cwd: repo, stdio: "ignore" });
+    execSync('git config user.email "test@example.com"', { cwd: repo });
+    execSync('git config user.name "Test"', { cwd: repo });
+    writeFileSync(join(repo, "README.md"), "ok\n");
+    execSync("git add README.md", { cwd: repo });
+    execSync('git commit -m "init"', { cwd: repo, stdio: "ignore" });
+    execSync(`git worktree add ${wt} -b fusion/fn-5058-test`, { cwd: repo, stdio: "ignore" });
+    rmSync(wt, { recursive: true, force: true });
+
+    await pruneWorktreeAdminEntries({ rootDir: repo, reason: "integration", target: wt });
+
+    rmSync(root, { recursive: true, force: true });
+  });
+});

packages/engine/src/__tests__/worktree-pool.test.ts

@@ -49,7 +49,12 @@ vi.mock("node:fs", () => ({
   rmSync: vi.fn(),
 }));
 
+vi.mock("../worktree-prune.js", () => ({
+  pruneWorktreeAdminEntries: vi.fn().mockResolvedValue(undefined),
+}));
+
 import * as desktopArtifacts from "../worktree-desktop-artifacts.js";
+import * as worktreePrune from "../worktree-prune.js";
 import {
   WorktreePool,
   getRegisteredWorktreeBranchMap,
@@ -71,6 +76,7 @@ const mockedExistsSync = vi.mocked(existsSync);
 const mockedLstatSync = vi.mocked(lstatSync);
 const mockedReaddirSync = vi.mocked(readdirSync);
 const mockedRmSync = vi.mocked(rmSync);
+const mockedPruneWorktreeAdminEntries = vi.mocked(worktreePrune.pruneWorktreeAdminEntries);
 const TEST_TASK_ID = "FN-test";
 
 let errorSpy: ReturnType<typeof vi.spyOn>;
@@ -847,6 +853,7 @@ describe("cleanupOrphanedWorktrees", () => {
     vi.clearAllMocks();
     mockedExistsSync.mockReturnValue(true);
     mockRegisteredWorktrees("/root", []);
+    mockedPruneWorktreeAdminEntries.mockResolvedValue(undefined);
   });
 
   it("removes worktrees not assigned to any active task", async () => {
@@ -997,6 +1004,9 @@ describe("cleanupOrphanedWorktrees", () => {
       recursive: true,
       force: true,
     });
+    expect(mockedPruneWorktreeAdminEntries).toHaveBeenCalledWith(
+      expect.objectContaining({ reason: "pool-cleanup-orphan", target: "/root/.worktrees/broken-wt" }),
+    );
   });
 });
 
@@ -1189,6 +1199,9 @@ describe("reapOrphanWorktrees", () => {
       recursive: true,
       force: true,
     });
+    expect(mockedPruneWorktreeAdminEntries).toHaveBeenCalledWith(
+      expect.objectContaining({ reason: "pool-reap-orphan", target: "/root/.worktrees/pale-raven" }),
+    );
   });
 
   it("does NOT remove a directory that is a registered git worktree", async () => {

packages/engine/src/index.ts

@@ -93,6 +93,11 @@ export {
 } from "./agent-instructions.js";
 export { HEARTBEAT_PROCEDURE, HEARTBEAT_SYSTEM_PROMPT, HEARTBEAT_NO_TASK_SYSTEM_PROMPT } from "./agent-heartbeat.js";
 export { WorktreePool, scanIdleWorktrees, cleanupOrphanedWorktrees, reapOrphanWorktrees } from "./worktree-pool.js";
+export {
+  pruneWorktreeAdminEntries,
+  pruneWorktreeAdminEntriesSync,
+  type PruneWorktreeAdminEntriesOptions,
+} from "./worktree-prune.js";
 export {
   BranchConflictError,
   BranchCrossContaminationError,

packages/engine/src/run-audit.ts

@@ -120,6 +120,18 @@ export type GitMutationType =
   | "worktree:worktrunk-fallback"
   | "worktree:worktrunk-failure"
   | "worktree:worktrunk-fallback-native"
+  /**
+   * Metadata shape:
+   * ```ts
+   * {
+   *   success: boolean;
+   *   reason: string;
+   *   target?: string;
+   *   error?: string;
+   * }
+   * ```
+   */
+  | "worktree:admin-entry-pruned"
   | "worktree:removal-refused-active-session"
   | "worktree:removal-forced-over-active-session"
   | "worktree:stale-lock-detected"

packages/engine/src/step-session-executor.ts

@@ -50,6 +50,7 @@ import {
   createTaskLogTool,
 } from "./agent-tools.js";
 import { RemovalReason, removeWorktree } from "./worktree-backend.js";
+import { pruneWorktreeAdminEntries } from "./worktree-prune.js";
 import { activeSessionRegistry } from "./active-session-registry.js";
 
 const stepExecLog = createLogger("step-session-executor");
@@ -1343,6 +1344,12 @@ Follow instructions precisely and avoid unrelated changes.`,
         // best-effort cleanup; log but don't mask the original error
         stepExecLog.log(`Warning: failed to remove partial worktree directory after creation failure: ${worktreePath}`);
       }
+      await pruneWorktreeAdminEntries({
+        rootDir,
+        reason: "step-session-create-failed",
+        target: worktreePath,
+        logger: stepExecLog,
+      }).catch(() => undefined);
       throw err;
     }
 
@@ -1357,6 +1364,12 @@ Follow instructions precisely and avoid unrelated changes.`,
       } catch {
         stepExecLog.log(`Warning: failed to remove worktree after identity-guard install failure: ${worktreePath}`);
       }
+      await pruneWorktreeAdminEntries({
+        rootDir,
+        reason: "step-session-guard-failed",
+        target: worktreePath,
+        logger: stepExecLog,
+      }).catch(() => undefined);
       throw err;
     }
 

packages/engine/src/worktree-backend.ts

@@ -10,6 +10,7 @@ import { resolveTaskWorktreePath } from "./worktree-paths.js";
 import { inspectBranchConflict } from "./branch-conflicts.js";
 import { formatError } from "./logger.js";
 import { installTaskWorktreeIdentityGuard } from "./worktree-hooks.js";
+import { pruneWorktreeAdminEntries } from "./worktree-prune.js";
 import {
   StaleWorktreeIndexLockError,
   classifyStaleLock,
@@ -187,6 +188,13 @@ export class NativeWorktreeBackend implements WorktreeBackend {
           timeout: REMOVE_TIMEOUT_MS,
           maxBuffer: MAX_BUFFER,
         }).catch(() => undefined);
+        await pruneWorktreeAdminEntries({
+          rootDir: input.rootDir,
+          auditor: this.deps.audit,
+          reason: "backend-guard-failed",
+          target: worktreePath,
+          logger: this.deps.logger,
+        }).catch(() => undefined);
         throw error;
       }
     };
@@ -363,6 +371,7 @@ export class WorktrunkWorktreeBackend implements WorktreeBackend {
     private readonly deps: {
       binaryPath: string | (() => Promise<string | null>) | null;
       logger?: { log: (m: string) => void; warn: (m: string) => void };
+      audit?: Pick<RunAuditor, "git">;
     },
   ) {}
 
@@ -475,6 +484,13 @@ export class WorktrunkWorktreeBackend implements WorktreeBackend {
         timeout: REMOVE_TIMEOUT_MS,
         maxBuffer: MAX_BUFFER,
       }).catch(() => undefined);
+      await pruneWorktreeAdminEntries({
+        rootDir: input.rootDir,
+        auditor: this.deps.audit,
+        reason: "backend-guard-failed",
+        target: resolvedPath,
+        logger: this.deps.logger,
+      }).catch(() => undefined);
       throw error;
     }
     return { path: resolvedPath, branch: input.branch };

packages/engine/src/worktree-pool.ts

@@ -17,6 +17,7 @@ import {
 import { cleanupSecretsEnvFile } from "./secrets-env-writer.js";
 import { removeDesktopBuildArtifacts } from "./worktree-desktop-artifacts.js";
 import type { RunAuditor } from "./run-audit.js";
+import { pruneWorktreeAdminEntries } from "./worktree-prune.js";
 
 export {
   NativeWorktreeBackend,
@@ -695,6 +696,12 @@ export async function cleanupOrphanedWorktrees(
           throw new Error(`Refusing to remove path outside .worktrees: ${worktreePath}`);
         }
         rmSync(worktreePath, { recursive: true, force: true });
+        await pruneWorktreeAdminEntries({
+          rootDir,
+          reason: "pool-cleanup-orphan",
+          target: worktreePath,
+          logger: worktreePoolLog,
+        }).catch(() => undefined);
       }
       worktreePoolLog.log(`Cleaned up orphaned worktree: ${worktreePath}`);
       cleaned++;
@@ -805,6 +812,12 @@ export async function reapOrphanWorktrees(
         worktreePoolLog.warn(`secrets-env cleanup failed for orphan ${name}: ${error instanceof Error ? error.message : String(error)}`);
       }
       rmSync(resolvedFull, { recursive: true, force: true });
+      await pruneWorktreeAdminEntries({
+        rootDir: projectRoot,
+        reason: "pool-reap-orphan",
+        target: resolvedFull,
+        logger: worktreePoolLog,
+      }).catch(() => undefined);
       worktreePoolLog.log(`reapOrphanWorktrees: removed half-initialized orphan ${name}`);
       removed++;
     } catch (err: unknown) {

packages/engine/src/worktree-prune.ts

@@ -0,0 +1,96 @@
+import { exec, execSync } from "node:child_process";
+import { promisify } from "node:util";
+
+import type { RunAuditor } from "./run-audit.js";
+
+const execAsync = promisify(exec);
+const PRUNE_TIMEOUT_MS = 30_000;
+const PRUNE_MAX_BUFFER = 10 * 1024 * 1024;
+
+type PruneAuditPayload = {
+  success: boolean;
+  reason: string;
+  target?: string;
+  error?: string;
+};
+
+export type PruneWorktreeAdminEntriesOptions = {
+  rootDir: string;
+  auditor?: Pick<RunAuditor, "git">;
+  reason: string;
+  target?: string;
+  logger?: { log: (m: string) => void };
+};
+
+async function emitAudit(
+  opts: PruneWorktreeAdminEntriesOptions,
+  metadata: PruneAuditPayload,
+): Promise<void> {
+  await opts.auditor?.git({
+    type: "worktree:admin-entry-pruned",
+    target: opts.target ?? opts.rootDir,
+    metadata,
+  });
+}
+
+export async function pruneWorktreeAdminEntries(opts: PruneWorktreeAdminEntriesOptions): Promise<void> {
+  try {
+    await execAsync("git worktree prune", {
+      cwd: opts.rootDir,
+      timeout: PRUNE_TIMEOUT_MS,
+      maxBuffer: PRUNE_MAX_BUFFER,
+      encoding: "utf-8",
+    });
+
+    opts.logger?.log?.(
+      `[worktree-prune] git worktree prune succeeded (reason=${opts.reason}${opts.target ? ` target=${opts.target}` : ""})`,
+    );
+    await emitAudit(opts, {
+      success: true,
+      reason: opts.reason,
+      target: opts.target,
+    });
+  } catch (error) {
+    const errorMessage = error instanceof Error ? error.message : String(error);
+    opts.logger?.log?.(
+      `[worktree-prune] git worktree prune failed (reason=${opts.reason}${opts.target ? ` target=${opts.target}` : ""}): ${errorMessage}`,
+    );
+    await emitAudit(opts, {
+      success: false,
+      reason: opts.reason,
+      target: opts.target,
+      error: errorMessage,
+    });
+  }
+}
+
+export function pruneWorktreeAdminEntriesSync(opts: PruneWorktreeAdminEntriesOptions): void {
+  try {
+    execSync("git worktree prune", {
+      cwd: opts.rootDir,
+      timeout: PRUNE_TIMEOUT_MS,
+      maxBuffer: PRUNE_MAX_BUFFER,
+      encoding: "utf-8",
+    });
+
+    opts.logger?.log?.(
+      `[worktree-prune] git worktree prune (sync) succeeded (reason=${opts.reason}${opts.target ? ` target=${opts.target}` : ""})`,
+    );
+    void emitAudit(opts, {
+      success: true,
+      reason: opts.reason,
+      target: opts.target,
+    });
+  } catch (error) {
+    const errorMessage = error instanceof Error ? error.message : String(error);
+    opts.logger?.log?.(
+      `[worktree-prune] git worktree prune (sync) failed (reason=${opts.reason}${opts.target ? ` target=${opts.target}` : ""}): ${errorMessage}`,
+    );
+    void emitAudit(opts, {
+      success: false,
+      reason: opts.reason,
+      target: opts.target,
+      error: errorMessage,
+    });
+  }
+}