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/unique-slug/package.json

@@ -0,0 +1,23 @@
+{
+  "name": "unique-slug",
+  "version": "2.0.2",
+  "description": "Generate a unique character string suitible for use in files and URLs.",
+  "main": "index.js",
+  "scripts": {
+    "test": "standard && tap --coverage test"
+  },
+  "keywords": [],
+  "author": "Rebecca Turner <me@re-becca.org> (http://re-becca.org)",
+  "license": "ISC",
+  "devDependencies": {
+    "standard": "^12.0.1",
+    "tap": "^12.7.0"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git://github.com/iarna/unique-slug.git"
+  },
+  "dependencies": {
+    "imurmurhash": "^0.1.4"
+  }
+}