feat(design): glass surfaces by role, the static Badge, LinkButton, user pickers on the Combobox (E28 S3d1)

frontend/src/components/ui/form.tsx

@@ -1,6 +1,7 @@
 import type { ReactNode } from "react";
 import Tooltip from "./Tooltip";
 import { FocusSafeButton } from "./FocusSafeButton";
+import { SURFACE } from "./surfaces";
 
 // Shared form/settings primitives, factored out of the many panels that each re-declared
 // them (Settings, Config, Stats, admin pages, Setup wizard). Visual contract unchanged.
@@ -51,7 +52,7 @@ export function Section({
   children: ReactNode;
 }) {
   return (
-    <div className={card ? "glass rounded-2xl p-4 mb-4" : "mb-6"}>
+    <div className={card ? `${SURFACE.panel} p-4 mb-4` : "mb-6"}>
       <div className={`text-xs uppercase tracking-wide text-muted ${card ? "mb-3" : "mb-2"}`}>
         {title}
       </div>