feat: improve book reviews, restore detailed privacy policy, fix header logo, add theme toggle, integrate boneyard-js

- Book reviews: add line-clamp for longer review text with expand/collapse per review
- Privacy policy: restore full detailed DSGVO-compliant fallback content
- Header (legal pages): change logo from 'dk' to 'dk0' in circle
- Header (main page): add ThemeToggle for dark/light mode switching
- Skeleton loading: integrate boneyard-js for ReadBooks, CurrentlyReading, Projects
- Add boneyard.config.json and bones/registry.ts placeholder

app/components/ClientProviders.tsx

@@ -7,6 +7,7 @@ import { ToastProvider } from "@/components/Toast";
 import ErrorBoundary from "@/components/ErrorBoundary";
 import { ConsentProvider } from "./ConsentProvider";
 import { ThemeProvider } from "./ThemeProvider";
+import "../../bones/registry";
 
 const BackgroundBlobs = dynamic(
   () => import("@/components/BackgroundBlobs").catch(() => ({ default: () => null })),