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/buffer-from/package.json

@@ -0,0 +1,19 @@
+{
+  "name": "buffer-from",
+  "version": "1.1.2",
+  "license": "MIT",
+  "repository": "LinusU/buffer-from",
+  "files": [
+    "index.js"
+  ],
+  "scripts": {
+    "test": "standard && node test"
+  },
+  "devDependencies": {
+    "standard": "^12.0.1"
+  },
+  "keywords": [
+    "buffer",
+    "buffer from"
+  ]
+}