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/tar/lib/get-write-flag.js

@@ -0,0 +1,20 @@
+// Get the appropriate flag to use for creating files
+// We use fmap on Windows platforms for files less than
+// 512kb.  This is a fairly low limit, but avoids making
+// things slower in some cases.  Since most of what this
+// library is used for is extracting tarballs of many
+// relatively small files in npm packages and the like,
+// it can be a big boost on Windows platforms.
+// Only supported in Node v12.9.0 and above.
+const platform = process.env.__FAKE_PLATFORM__ || process.platform
+const isWindows = platform === 'win32'
+const fs = global.__FAKE_TESTING_FS__ || require('fs')
+
+/* istanbul ignore next */
+const { O_CREAT, O_TRUNC, O_WRONLY, UV_FS_O_FILEMAP = 0 } = fs.constants
+
+const fMapEnabled = isWindows && !!UV_FS_O_FILEMAP
+const fMapLimit = 512 * 1024
+const fMapFlag = UV_FS_O_FILEMAP | O_TRUNC | O_CREAT | O_WRONLY
+module.exports = !fMapEnabled ? () => 'w'
+  : size => size < fMapLimit ? fMapFlag : 'w'