Consolidate theme radius/shadow props and make rounded utilities responsive

- Remove duplicate roundedness/shadowLevel props (keep radius/shadow)
- Switch globals.css radius scale to proportional (square→pill works)
- Replace rounded-full with rounded-md on theme-driven elements
- Remove banner props from Navigation, drop publishing overlay

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

components/navigation/navigation.editor.tsx

@@ -22,8 +22,6 @@ export const navigationEditor: ComponentConfig<NavigationProps> = {
     showCart: "yes",
     sticky: "yes",
     tone: "default",
-    bannerText: "",
-    bannerTone: "accent",
   },
   fields: {
     brand: { label: "Brand", type: "text", contentEditable: true },
@@ -38,20 +36,6 @@ export const navigationEditor: ComponentConfig<NavigationProps> = {
         href: { label: "Link", type: "text" },
       },
     },
-    bannerText: {
-      label: "Banner text",
-      type: "text",
-      contentEditable: true,
-    },
-    bannerTone: {
-      label: "Banner tone",
-      type: "select",
-      options: [
-        { label: "Default", value: "default" },
-        { label: "Accent", value: "accent" },
-        { label: "Inverse (dark)", value: "inverse" },
-      ],
-    },
     showSearch: {
       label: "Search icon",
       type: "radio",