feat(float): rebuild right floating buttons 1:1 with reference theme

- Storage: aksrt_floating_buttons now uses reference float_btn shape
  (fixed 8 sortable types, more-buttons group); single source of
  defaults/sanitize in AKSRT\Settings\FloatButtons
- Admin SPA: CSF-parity page split into components/floating/*
- Frontend: aksrt_float_right() on wp_footer mirrors zib_float_right()
  (wp_is_mobile, PC tooltip, toggle-theme, ontop/scrollTopTo, qrcode,
  wechat/qq, pay_vip, add, more)
- CSS: floating-buttons.css rewritten from reference rules; legacy float
  rules removed from main/part/shell/overlay-primitives
- Remove dead code: reorder route/API, get_floating_buttons_items,
  floatingSchema, floatActionsId, float-theme-toggle bindings,
  common/floating.css, aksrt-runtime-win.php, .aksrt-float-btn

src/Admin/GlobalController.php

@@ -47,11 +47,6 @@ class GlobalController extends ControllerBase {
             'callback'            => [$this, 'rest_handle_floating_buttons'],
             'permission_callback' => [$this, 'check_permission'],
         ]);
-        register_rest_route(self::API_NAMESPACE, '/settings/floating-buttons/reorder', [
-            'methods'             => 'POST',
-            'callback'            => [$this, 'rest_reorder_floating_buttons'],
-            'permission_callback' => [$this, 'check_permission'],
-        ]);
 
         // Friend Links
         register_rest_route(self::API_NAMESPACE, '/friend-links', [