chore(deps): refresh locks and harden engine promotion

- refresh compatible npm and Cargo lockfile dependencies
- update locked Windows and Linux FFmpeg provider artifacts by checksum
- publish verified engine payloads with interrupted-promotion recovery
- retry Windows-safe cleanup and cover worst-case promotion states

scripts/engine-payload-promotion.node-test.js

@@ -0,0 +1,128 @@
+import assert from 'node:assert/strict';
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import test from 'node:test';
+import {
+  promoteDirectory,
+  recoverInterruptedPromotion,
+  removePathWithRetry,
+} from './engine-payload-promotion.js';
+
+function temporaryDirectory() {
+  return fs.mkdtempSync(path.join(os.tmpdir(), 'firelink-payload-promotion-'));
+}
+
+test('promotes a verified staging directory and replaces the previous payload', async () => {
+  const root = temporaryDirectory();
+  try {
+    const destination = path.join(root, 'target');
+    const staging = path.join(root, 'staging', 'payload');
+    fs.mkdirSync(destination, { recursive: true });
+    fs.writeFileSync(path.join(destination, 'engine'), 'old');
+    fs.mkdirSync(staging, { recursive: true });
+    fs.writeFileSync(path.join(staging, 'engine'), 'new');
+
+    await promoteDirectory(staging, destination);
+
+    assert.equal(fs.readFileSync(path.join(destination, 'engine'), 'utf8'), 'new');
+    assert.equal(fs.existsSync(staging), false);
+    assert.equal(fs.readdirSync(root).some(name => name.includes('.previous-')), false);
+  } finally {
+    fs.rmSync(root, { recursive: true, force: true });
+  }
+});
+
+test('rejects an invalid staging path without removing the previous payload', async () => {
+  const root = temporaryDirectory();
+  try {
+    const destination = path.join(root, 'target');
+    const staging = path.join(root, 'staging-file');
+    fs.mkdirSync(destination, { recursive: true });
+    fs.writeFileSync(path.join(destination, 'engine'), 'old');
+    fs.writeFileSync(staging, 'not a directory');
+
+    await assert.rejects(() => promoteDirectory(staging, destination), /not a directory/);
+    assert.equal(fs.readFileSync(path.join(destination, 'engine'), 'utf8'), 'old');
+  } finally {
+    fs.rmSync(root, { recursive: true, force: true });
+  }
+});
+
+test('recovers one interrupted previous payload before publishing a replacement', async () => {
+  const root = temporaryDirectory();
+  try {
+    const destination = path.join(root, 'target');
+    const backup = path.join(root, '.target.previous-123-456');
+    const staging = path.join(root, 'staging', 'payload');
+    fs.mkdirSync(backup, { recursive: true });
+    fs.writeFileSync(path.join(backup, 'engine'), 'old');
+    fs.mkdirSync(staging, { recursive: true });
+    fs.writeFileSync(path.join(staging, 'engine'), 'new');
+
+    await promoteDirectory(staging, destination);
+
+    assert.equal(fs.readFileSync(path.join(destination, 'engine'), 'utf8'), 'new');
+    assert.equal(fs.existsSync(backup), false);
+  } finally {
+    fs.rmSync(root, { recursive: true, force: true });
+  }
+});
+
+test('fails closed when interrupted recovery has multiple candidates', () => {
+  const root = temporaryDirectory();
+  try {
+    const destination = path.join(root, 'target');
+    const firstBackup = path.join(root, '.target.previous-123-456');
+    const secondBackup = path.join(root, '.target.previous-789-012');
+    fs.mkdirSync(firstBackup, { recursive: true });
+    fs.mkdirSync(secondBackup, { recursive: true });
+
+    assert.throws(
+      () => recoverInterruptedPromotion(destination),
+      /found 2 previous payloads/
+    );
+    assert.equal(fs.existsSync(destination), false);
+    assert.equal(fs.existsSync(firstBackup), true);
+    assert.equal(fs.existsSync(secondBackup), true);
+  } finally {
+    fs.rmSync(root, { recursive: true, force: true });
+  }
+});
+
+test('removes a temporary payload tree after it becomes disposable', async () => {
+  const root = temporaryDirectory();
+  try {
+    const temporary = path.join(root, 'temporary');
+    fs.mkdirSync(path.join(temporary, 'nested'), { recursive: true });
+    fs.writeFileSync(path.join(temporary, 'nested', 'archive'), 'payload');
+
+    await removePathWithRetry(temporary);
+
+    assert.equal(fs.existsSync(temporary), false);
+  } finally {
+    fs.rmSync(root, { recursive: true, force: true });
+  }
+});
+
+test('removes orphaned backups from dead provisioners after a successful publish', async () => {
+  const root = temporaryDirectory();
+  try {
+    const destination = path.join(root, 'target');
+    const orphanedBackup = path.join(root, '.target.previous-999999999-123456');
+    const staging = path.join(root, 'staging', 'payload');
+    fs.mkdirSync(destination, { recursive: true });
+    fs.writeFileSync(path.join(destination, 'engine'), 'old');
+    fs.mkdirSync(orphanedBackup, { recursive: true });
+    fs.writeFileSync(path.join(orphanedBackup, 'engine'), 'orphaned');
+    fs.mkdirSync(staging, { recursive: true });
+    fs.writeFileSync(path.join(staging, 'engine'), 'new');
+
+    await promoteDirectory(staging, destination);
+
+    assert.equal(fs.existsSync(orphanedBackup), false);
+    assert.equal(fs.readFileSync(path.join(destination, 'engine'), 'utf8'), 'new');
+  } finally {
+    fs.rmSync(root, { recursive: true, force: true });
+  }
+});