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/js/core/theme.js

@@ -159,12 +159,12 @@
     dispatchThemeChange(isDark);
     // Icon visibility is CSS-driven via html.dark / body.theme-dark.
     // Only sync a11y state here — do not set inline display (fights !important CSS).
-    document.querySelectorAll("#theme-toggle, #theme-toggle-desktop, #theme-toggle-mobile, #dropdown-theme-toggle, #float-theme-toggle, .toggle-theme, .theme-toggle-btn, [data-action='toggle-theme']").forEach(function (btn) {
+    document.querySelectorAll("#theme-toggle, #theme-toggle-desktop, #theme-toggle-mobile, #dropdown-theme-toggle, .toggle-theme, [data-action='toggle-theme']").forEach(function (btn) {
       if (!btn) return;
       btn.setAttribute("aria-pressed", isDark ? "true" : "false");
       btn.classList.toggle("is-dark", isDark);
-      var moon = btn.querySelector(".theme-icon-moon, .float-btn__icon-moon");
-      var sun = btn.querySelector(".theme-icon-sun, .float-btn__icon-sun");
+      var moon = btn.querySelector(".theme-icon-moon");
+      var sun = btn.querySelector(".theme-icon-sun");
       if (moon) {
         moon.removeAttribute("style");
         moon.setAttribute("aria-hidden", isDark ? "true" : "false");
@@ -174,10 +174,6 @@
         sun.setAttribute("aria-hidden", isDark ? "false" : "true");
       }
     });
-    var floatBtn = document.getElementById("float-theme-toggle");
-    if (floatBtn) {
-      floatBtn.setAttribute("aria-pressed", isDark ? "true" : "false");
-    }
     var ddBtn = document.getElementById("dropdown-theme-toggle");
     if (ddBtn) ddBtn.setAttribute("aria-pressed", isDark ? "true" : "false");
   }
@@ -260,7 +256,6 @@
     bindToggle("theme-toggle");
     bindToggle("theme-toggle-desktop");
     bindToggle("dropdown-theme-toggle");
-    bindToggle("float-theme-toggle");
     bindToggle("theme-toggle-mobile");
   }