Galerie aller shadcn/ui-Komponenten auf der Startseite

- Alle 63 Komponenten aus dem shadcn-Register installiert (Stil base-luma)
- Galerie unter components/galerie mit 7 Kategorien und Sprungnavigation
- Inhaltsbreite auf max-w-6xl erweitert
- shadcn-Hauptfarbe auf E&P-Tiefblau, größter Radius eckig
- App-Titel "UI-Galerie"

Co-Authored-By: Claude Opus 5.5 <[email protected]>

frontend-starter/hooks/use-highlighted-code.ts

@@ -0,0 +1,75 @@
+import * as React from "react"
+
+import { loadHighlighter } from "@/lib/highlighter"
+
+export function useHighlightedCode(value: string, language: string) {
+  // A trailing newline would render as an extra empty line.
+  const code = value.endsWith("\n") ? value.slice(0, -1) : value
+  const [loaded, setLoaded] = React.useState<{
+    language: string
+    highlighter: Awaited<ReturnType<typeof loadHighlighter>>
+  } | null>(null)
+  const highlighter = loaded?.language === language ? loaded.highlighter : null
+
+  React.useEffect(() => {
+    let cancelled = false
+
+    loadHighlighter(language)
+      .then((next) => {
+        if (!cancelled) {
+          setLoaded({ language, highlighter: next })
+        }
+      })
+      .catch(() => {})
+
+    return () => {
+      cancelled = true
+    }
+  }, [language])
+
+  // The complete lines, highlighted. While the code streams, only the new
+  // lines are tokenized, starting from the grammar state of the last one.
+  const [done, setDone] = React.useState<{
+    highlighter: typeof highlighter
+    text: string
+    lines: React.ReactNode[]
+    state?: Parameters<NonNullable<typeof highlighter>["highlight"]>[1]
+  }>({ highlighter: null, text: "", lines: [] })
+
+  let next = done
+
+  if (next.highlighter !== highlighter || !code.startsWith(next.text)) {
+    next = { highlighter, text: "", lines: [] }
+  }
+
+  const end = code.lastIndexOf("\n") + 1
+
+  if (highlighter && end > next.text.length) {
+    const result = highlighter.highlight(
+      code.slice(next.text.length, end - 1),
+      next.state
+    )
+
+    next = {
+      highlighter,
+      text: code.slice(0, end),
+      lines: [...next.lines, ...result.lines],
+      state: result.state,
+    }
+  }
+
+  if (next !== done) {
+    setDone(next)
+  }
+
+  // The last line is still being written, so it is tokenized on every render.
+  const tail = code.slice(end)
+
+  return React.useMemo(() => {
+    if (!highlighter) {
+      return code.split("\n")
+    }
+
+    return [...next.lines, highlighter.highlight(tail, next.state).lines[0]]
+  }, [code, highlighter, next, tail])
+}