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/retry/.travis.yml

@@ -0,0 +1,15 @@
+language: node_js
+node_js:
+  - "4"
+before_install:
+  - pip install --user codecov
+after_success:
+  - codecov --file coverage/lcov.info --disable search
+# travis encrypt [subdomain]:[api token]@[room id]
+# notifications:
+#   email: false
+#   campfire:
+#     rooms:
+#       secure: xyz
+#     on_failure: always
+#     on_success: always