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/Core/ScriptsPart1c.php

@@ -532,7 +532,6 @@ trait ScriptsPart1c {
                 'searchPanelId'  => 'nav-search-panel',
                 'drawerId'       => 'mobile-navbar',
                 'userMenuId'     => 'sub-user-box',
-                'floatActionsId' => 'float-right-btns',
                 'tabbarId'       => 'footer-tabbar',
             ],
 			'themeUri'              => get_template_directory_uri(),