feat: plakat redesign phase 3 (windows on desktop, sheets on mobile)

- Tapping an object on the desk opens a window (desktop) or a bottom sheet
  (mobile) instead of flipping: projects, now, servers, reading, about, contact
- Desktop windows in poster style (2px ink rule, hard offset shadow), open
  from the tapped object, thrown by the title bar with momentum and elastic
  viewport edges, stack by focus, minimize into a tray, Escape closes the top
  window, focus moves to close and returns to the trigger
- Mobile sheets via vaul 1.1.2: drag down to dismiss, overlay, focus trap
- Project window shows live/source links from Directus when present
- Hero "Write me" opens the contact window; still a plain #contact link
  without JavaScript
- Shared current-book loader for desk, deck and reading window
- Texts in de/en, i18n key check extended

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

app/components/tisch/currentBook.ts

@@ -0,0 +1,24 @@
+// Aktuelles Buch aus Hardcover (über n8n). Tisch, Stapel und Lese-Fenster teilen sich eine Anfrage.
+
+export interface CurrentBook {
+  title: string;
+  authors: string[];
+  image: string | null;
+  progress: number;
+}
+
+// Tisch und Stapel zeigen das Buch beide; so wird es nur einmal geladen
+let bookRequest: Promise<CurrentBook | null> | null = null;
+export function loadCurrentBook(): Promise<CurrentBook | null> {
+  if (!bookRequest) {
+    bookRequest = fetch("/api/n8n/hardcover/currently-reading")
+      .then((res) => (res.ok ? res.json() : null))
+      .then((data) => {
+        const list = data?.currentlyReading;
+        const first = Array.isArray(list) ? list[0] : list;
+        return first ?? null;
+      })
+      .catch(() => null);
+  }
+  return bookRequest;
+}