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/fs-constants/README.md

@@ -0,0 +1,26 @@
+# fs-constants
+
+Small module that allows you to get the fs constants across
+Node and the browser. 
+
+```
+npm install fs-constants
+```
+
+Previously you would use `require('constants')` for this in node but that has been
+deprecated and changed to `require('fs').constants` which does not browserify.
+
+This module uses `require('constants')` in the browser and `require('fs').constants` in node to work around this
+
+
+## Usage
+
+``` js
+var constants = require('fs-constants')
+
+console.log('constants:', constants)
+```
+
+## License
+
+MIT