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/content/rm.js

@@ -0,0 +1,19 @@
+'use strict'
+
+const util = require('util')
+
+const contentPath = require('./path')
+const { hasContent } = require('./read')
+const rimraf = util.promisify(require('rimraf'))
+
+module.exports = rm
+
+function rm (cache, integrity) {
+  return hasContent(cache, integrity).then((content) => {
+    // ~pretty~ sure we can't end up with a content lacking sri, but be safe
+    if (content && content.sri)
+      return rimraf(contentPath(cache, content.sri)).then(() => true)
+    else
+      return false
+  })
+}