Marketing Hub: RBAC, i18n (AR/EN), tasks overhaul, team/user merge, tutorial

Features:
- Full RBAC with 3 roles (superadmin/manager/contributor)
- Ownership tracking on posts, tasks, campaigns, projects
- Task system: assign to anyone, filter combobox, visibility scoping
- Team members merged into users table (single source of truth)
- Post thumbnails on kanban cards from attachments
- Publication link validation before publishing
- Interactive onboarding tutorial with Settings restart
- Full Arabic/English i18n with RTL layout support
- Language toggle in sidebar, IBM Plex Sans Arabic font
- Brand-based visibility filtering for non-superadmins
- Manager can only create contributors
- Profile completion flow for new users
- Cookie-based sessions (express-session + SQLite)

server/node_modules/better-sqlite3/lib/methods/serialize.js

@@ -0,0 +1,16 @@
+'use strict';
+const { cppdb } = require('../util');
+
+module.exports = function serialize(options) {
+	if (options == null) options = {};
+
+	// Validate arguments
+	if (typeof options !== 'object') throw new TypeError('Expected first argument to be an options object');
+
+	// Interpret and validate options
+	const attachedName = 'attached' in options ? options.attached : 'main';
+	if (typeof attachedName !== 'string') throw new TypeError('Expected the "attached" option to be a string');
+	if (!attachedName) throw new TypeError('The "attached" option cannot be an empty string');
+
+	return this[cppdb].serialize(attachedName);
+};