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/cacache/lib/util/disposer.js

@@ -0,0 +1,30 @@
+'use strict'
+
+module.exports.disposer = disposer
+
+function disposer (creatorFn, disposerFn, fn) {
+  const runDisposer = (resource, result, shouldThrow = false) => {
+    return disposerFn(resource)
+      .then(
+        // disposer resolved, do something with original fn's promise
+        () => {
+          if (shouldThrow)
+            throw result
+
+          return result
+        },
+        // Disposer fn failed, crash process
+        (err) => {
+          throw err
+          // Or process.exit?
+        })
+  }
+
+  return creatorFn
+    .then((resource) => {
+      // fn(resource) can throw, so wrap in a promise here
+      return Promise.resolve().then(() => fn(resource))
+        .then((result) => runDisposer(resource, result))
+        .catch((err) => runDisposer(resource, err, true))
+    })
+}