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/promise-inflight/README.md

@@ -0,0 +1,34 @@
+# promise-inflight
+
+One promise for multiple requests in flight to avoid async duplication
+
+## USAGE
+
+```javascript
+const inflight = require('promise-inflight')
+
+// some request that does some stuff
+function req(key) {
+  // key is any random string.  like a url or filename or whatever.
+  return inflight(key, () => {
+    // this is where you'd fetch the url or whatever
+    return Promise.delay(100)
+  })
+}
+
+// only assigns a single setTimeout
+// when it dings, all thens get called with the same result.  (There's only
+// one underlying promise.)
+req('foo').then(…)
+req('foo').then(…)
+req('foo').then(…)
+req('foo').then(…)
+```
+
+## SEE ALSO
+
+* [inflight](https://npmjs.com/package/inflight) - For the callback based function on which this is based.
+
+## STILL NEEDS
+
+Tests!