feat: Complete analytics implementation with all 7 pages, ROI calculation, conversion rate formatting, and chart improvements

includes/Api/Permissions.php

@@ -29,4 +29,12 @@ class Permissions {
         $nonce = $_SERVER['HTTP_X_WP_NONCE'] ?? '';
         return (bool) wp_verify_nonce($nonce, 'wp_rest');
     }
+
+    /**
+     * Check if user has admin/manage_woocommerce permission
+     * Used for analytics and admin-only endpoints
+     */
+    public static function check_admin_permission(): bool {
+        return current_user_can('manage_woocommerce') || current_user_can('manage_options');
+    }
 }