chore: rename package from @hykocx/zen to @zen/core

Update all references across source files, documentation, and
configuration to reflect the new package scope and name. This includes
updating `.npmrc` registry config, install instructions, module
examples, and all import path comments throughout the codebase.

src/features/admin/actions/statsActions.js

@@ -9,9 +9,9 @@
  * 
  * ```javascript
  * // app/(admin)/admin/[...admin]/page.js
- * import { protectAdmin } from '@hykocx/zen/admin';
- * import { getDashboardStats, getModuleDashboardStats } from '@hykocx/zen/admin/actions';
- * import { AdminPagesClient } from '@hykocx/zen/admin/pages';
+ * import { protectAdmin } from '@zen/core/admin';
+ * import { getDashboardStats, getModuleDashboardStats } from '@zen/core/admin/actions';
+ * import { AdminPagesClient } from '@zen/core/admin/pages';
  * 
  * export default async function AdminPage({ params }) {
  *   const { user } = await protectAdmin();
@@ -37,7 +37,7 @@
 
 'use server';
 
-import { query } from '@hykocx/zen/database';
+import { query } from '@zen/core/database';
 
 /**
  * Get total number of users