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/iconv-lite/lib/bom-handling.js

@@ -0,0 +1,52 @@
+"use strict";
+
+var BOMChar = '\uFEFF';
+
+exports.PrependBOM = PrependBOMWrapper
+function PrependBOMWrapper(encoder, options) {
+    this.encoder = encoder;
+    this.addBOM = true;
+}
+
+PrependBOMWrapper.prototype.write = function(str) {
+    if (this.addBOM) {
+        str = BOMChar + str;
+        this.addBOM = false;
+    }
+
+    return this.encoder.write(str);
+}
+
+PrependBOMWrapper.prototype.end = function() {
+    return this.encoder.end();
+}
+
+
+//------------------------------------------------------------------------------
+
+exports.StripBOM = StripBOMWrapper;
+function StripBOMWrapper(decoder, options) {
+    this.decoder = decoder;
+    this.pass = false;
+    this.options = options || {};
+}
+
+StripBOMWrapper.prototype.write = function(buf) {
+    var res = this.decoder.write(buf);
+    if (this.pass || !res)
+        return res;
+
+    if (res[0] === BOMChar) {
+        res = res.slice(1);
+        if (typeof this.options.stripBOM === 'function')
+            this.options.stripBOM();
+    }
+
+    this.pass = true;
+    return res;
+}
+
+StripBOMWrapper.prototype.end = function() {
+    return this.decoder.end();
+}
+