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

assets/admin/src/api/modules/global.js

@@ -11,7 +11,6 @@ export const globalApiMethods = {
 
   getFloatingButtons() { return this.request('/settings/floating-buttons') },
   saveFloatingButtons(data) { return this.request('/settings/floating-buttons', { method: 'POST', body: JSON.stringify(data) }) },
-  reorderFloatingButtons(ids) { return this.request('/settings/floating-buttons/reorder', { method: 'POST', body: JSON.stringify({ ids }) }) },
 
   getFriendLinks() { return this.request('/friend-links') },
   addFriendLink(data) { return this.request('/friend-links', { method: 'POST', body: JSON.stringify(data) }) },