Migrate codebase from CommonJS to ES Modules

- Convert all require()/module.exports to import/export across 260+ files
- Add "type": "module" to package.json to enable ESM by default
- Add migrations/package.json with "type": "commonjs" to keep db-migrate compatible
- Convert eslint.config.js to ESM with sourceType: "module"
- Replace __dirname/__filename with import.meta.dirname/import.meta.filename
- Replace require.main === module with process.argv[1] === import.meta.filename
- Remove 'use strict' directives (implicit in ESM)
- Convert dynamic require() in switch statements to static import lookup maps
  (dns.js, domains.js, backupformats.js, backupsites.js, network.js)
- Extract self-referencing exports.CONSTANT patterns into standalone const
  declarations (apps.js, services.js, locks.js, users.js, mail.js, etc.)
- Lazify SERVICES object in services.js to avoid circular dependency TDZ issues
- Add clearMailQueue() to mailer.js for ESM-safe queue clearing in tests
- Add _setMockApp() to ldapserver.js for ESM-safe test mocking
- Add _setMockResolve() wrapper to dig.js for ESM-safe DNS mocking in tests
- Convert backupupload.js to use dynamic imports so --check exits before
  loading the module graph (which requires BOX_ENV)
- Update check-install to use ESM import for infra_version.js
- Convert scripts/ (hotfix, release, remote_hotfix.js, find-unused-translations)
- All 1315 tests passing

Migration stats (AI-assisted using Cursor with Claude):
- Wall clock time: ~3-4 hours
- Assistant completions: ~80-100
- Estimated token usage: ~1-2M tokens

Co-authored-by: Cursor <cursoragent@cursor.com>

src/apptask.js

@@ -1,46 +1,49 @@
 #!/usr/bin/env node
 
-'use strict';
+import apps from './apps.js';
+import * as appstore from './appstore.js';
+import assert from 'node:assert';
+import AuditSource from './auditsource.js';
+import * as backupSites from './backupsites.js';
+import * as backuptask from './backuptask.js';
+import BoxError from './boxerror.js';
+import * as community from './community.js';
+import constants from './constants.js';
+import debugModule from 'debug';
+import * as df from './df.js';
+import * as dns from './dns.js';
+import * as docker from './docker.js';
+import ejs from 'ejs';
+import fs from 'node:fs';
+import { promises as fsPromises } from 'node:fs';
+import * as iputils from './iputils.js';
+import manifestFormat from '@cloudron/manifest-format';
+import os from 'node:os';
+import path from 'node:path';
+import paths from './paths.js';
+import promiseRetry from './promise-retry.js';
+import * as reverseProxy from './reverseproxy.js';
+import safe from 'safetydance';
+import services from './services.js';
+import shellModule from './shell.js';
+import * as _ from './underscore.js';
 
-exports = module.exports = {
+const debug = debugModule('box:apptask');
+const shell = shellModule('apptask');
+
+const _createAppDir = createAppDir;
+const _deleteAppDir = deleteAppDir;
+const _verifyManifest = verifyManifest;
+
+export {
     run,
-
-    // exported for testing
-    _createAppDir: createAppDir,
-    _deleteAppDir: deleteAppDir,
-    _verifyManifest: verifyManifest,
+    _createAppDir,
+    _deleteAppDir,
+    _verifyManifest,
 };
 
-const apps = require('./apps.js'),
-    appstore = require('./appstore.js'),
-    assert = require('node:assert'),
-    AuditSource = require('./auditsource.js'),
-    backupSites = require('./backupsites.js'),
-    backuptask = require('./backuptask.js'),
-    BoxError = require('./boxerror.js'),
-    community = require('./community.js'),
-    constants = require('./constants.js'),
-    debug = require('debug')('box:apptask'),
-    df = require('./df.js'),
-    dns = require('./dns.js'),
-    docker = require('./docker.js'),
-    ejs = require('ejs'),
-    fs = require('node:fs'),
-    fsPromises = require('node:fs').promises,
-    iputils = require('./iputils.js'),
-    manifestFormat = require('@cloudron/manifest-format'),
-    os = require('node:os'),
-    path = require('node:path'),
-    paths = require('./paths.js'),
-    promiseRetry = require('./promise-retry.js'),
-    reverseProxy = require('./reverseproxy.js'),
-    safe = require('safetydance'),
-    services = require('./services.js'),
-    shell = require('./shell.js')('apptask'),
-    _ = require('./underscore.js');
-
-const LOGROTATE_CONFIG_EJS = fs.readFileSync(__dirname + '/logrotate.ejs', { encoding: 'utf8' }),
-    CONFIGURE_LOGROTATE_CMD = path.join(__dirname, 'scripts/configurelogrotate.sh');
+const LOGROTATE_CONFIG_EJS = fs.readFileSync(import.meta.dirname + '/logrotate.ejs', { encoding: 'utf8' }),
+    CONFIGURE_LOGROTATE_CMD = path.join(import.meta.dirname, 'scripts/configurelogrotate.sh');
 
 function makeTaskError(error, app) {
     assert(error instanceof BoxError);
@@ -293,7 +296,6 @@ async function updateChecklist(app, newChecks, acknowledged = false) {
     await updateApp(app, { checklist });
 }
 
-
 async function startApp(app) {
     debug('startApp: starting container');