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/prebuild-install/help.txt

@@ -0,0 +1,16 @@
+prebuild-install [options]
+
+  --download    -d  [url]       (download prebuilds, no url means github)
+  --target      -t  version     (version to install for)
+  --runtime     -r  runtime     (Node runtime [node or electron] to build or install for, default is node)
+  --path        -p  path        (make a prebuild-install here)
+  --token       -T  gh-token    (github token for private repos)
+  --arch            arch        (target CPU architecture, see Node OS module docs, default is current arch)
+  --platform        platform    (target platform, see Node OS module docs, default is current platform)
+  --tag-prefix <prefix>         (github tag prefix, default is "v")
+  --force                       (always use prebuilt binaries when available)
+  --build-from-source           (skip prebuild download)
+  --verbose                     (log verbosely)
+  --libc                        (use provided libc rather than system default)
+  --debug                       (set Debug or Release configuration)
+  --version                     (print prebuild-install version and exit)