feat: unify referral promotion tabs and compact earnings UI

src/Credits/Invite.php

@@ -74,10 +74,10 @@ class Invite {
             ],
         ]);
     }
-    /** Capture ?ref=XYZ, with legacy ?invite=XYZ support. */
+    /** Capture the unified ?ref=XYZ referral parameter. */
     public function capture_invite_cookie(): void {
         if (is_admin()) return;
-        $raw_code = $_GET['ref'] ?? $_GET['invite'] ?? '';
+        $raw_code = $_GET['ref'] ?? '';
         if ($raw_code === '') return;
         // 邀请注册功能关闭时不处理
         if (class_exists('\AKSRT\Settings\Settings') && !\AKSRT\Settings\Settings::invite_registration_enabled()) return;