feat: plakat redesign phase 4 (chat window, contact, footer, cleanup) (#77)

- AI chat moves into a window/sheet, opened from a new speech-bubble card on
  the desk; it now respects the chatbot consent and asks before sending
  anything to n8n (previously it ignored the consent)
- Contact as red poster section with big mail address and the form on a paper
  card; validation errors are finally shown inline (aria-invalid, role=alert)
- Footer as ink strip with dk0 wordmark, legal links and a button to reopen
  the privacy settings
- "About me" in the header opens the about window on the home page
- Remove the old About section and its parts (BentoChat, ActivityFeed,
  CurrentlyReading, ReadBooks), the unused ChatWidget, Projects and BentoGrid,
  their tests, wrappers, loaders, types and texts
- scripts/directus-cleanup-redesign.mjs: dry run by default, --apply archives
  hobbies, tech stack categories and old content pages and deletes four
  unused message overrides after a full JSON backup; run only after the
  redesign is live on production

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/components/tisch/Board.tsx

@@ -155,7 +155,9 @@ function BoardItem({ obj, labels, spot, z, tableRef, onFront, register }: BoardI
   const openWindow = useOpenWindow();
   const elRef = useRef<HTMLDivElement | null>(null);
   const openIt = () => openWindow?.(windowFor(obj), elRef.current);
-  const radius = { sticker: "rounded-full", photo: "rounded-md", book: "rounded-[6px_14px_14px_6px]" }[obj.kind as string] ?? "rounded-2xl";
+  const radius =
+    { sticker: "rounded-full", photo: "rounded-md", book: "rounded-[6px_14px_14px_6px]", chat: "rounded-[22px_22px_22px_6px]" }[obj.kind as string] ??
+    "rounded-2xl";
 
   return (
     <motion.div