docs(storybook): simplify sidebar Story pages around the UI

Drop the category kicker from the 83 sidebar Stories (kicker is now optional;
hidden verification Stories keep it) and shorten or remove repeated, obvious
or internal page/section descriptions. Required specs, limits, virtual-data
and undecided-value notices stay. Story IDs, exports, fixtures, shared state
notes and package code are unchanged. Record: docs/reports/storybook-ui-simplification-2026-10-22.md

src/components/story-page.tsx

@@ -13,10 +13,12 @@ export function StoryPage({ className, children }: { className?: string; childre
   return <div className={className ? `sb-page ${className}` : "sb-page"}><div className="sb-page-inner">{children}</div></div>
 }
 
-export function StoryPageHeader({ kicker, title, description }: { kicker: string; title: string; description?: ReactNode }) {
+// Representative (sidebar) Stories omit `kicker`: the sidebar path already names the category.
+// Hidden verification Stories keep passing it so their page structure stays unchanged.
+export function StoryPageHeader({ kicker, title, description }: { kicker?: string; title: string; description?: ReactNode }) {
   return (
     <header className="sb-page-header">
-      <p className="sb-page-kicker">{kicker}</p>
+      {kicker ? <p className="sb-page-kicker">{kicker}</p> : null}
       <h1 className="sb-page-title">{title}</h1>
       {description ? <p className="sb-page-description">{description}</p> : null}
     </header>