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/isexe/windows.js

@@ -0,0 +1,42 @@
+module.exports = isexe
+isexe.sync = sync
+
+var fs = require('fs')
+
+function checkPathExt (path, options) {
+  var pathext = options.pathExt !== undefined ?
+    options.pathExt : process.env.PATHEXT
+
+  if (!pathext) {
+    return true
+  }
+
+  pathext = pathext.split(';')
+  if (pathext.indexOf('') !== -1) {
+    return true
+  }
+  for (var i = 0; i < pathext.length; i++) {
+    var p = pathext[i].toLowerCase()
+    if (p && path.substr(-p.length).toLowerCase() === p) {
+      return true
+    }
+  }
+  return false
+}
+
+function checkStat (stat, path, options) {
+  if (!stat.isSymbolicLink() && !stat.isFile()) {
+    return false
+  }
+  return checkPathExt(path, options)
+}
+
+function isexe (path, options, cb) {
+  fs.stat(path, function (er, stat) {
+    cb(er, er ? false : checkStat(stat, path, options))
+  })
+}
+
+function sync (path, options) {
+  return checkStat(fs.statSync(path), path, options)
+}