chore: CSP script nonces, deploy health check, dead-code cleanup

Add per-request CSP nonces (drop script unsafe-inline), post-deploy /api/health gate, bump next-auth to beta.32, and remove unused motion/cache/permission helpers.

Co-authored-by: Cursor <[email protected]>

src/lib/cache.ts

@@ -15,8 +15,3 @@ export function cached<T>(
 		return data;
 	});
 }
-
-// TODO: Check of dit weg kan — niet geïmporteerd in de codebase
-export function bustCache(key: string): void {
-	store.delete(key);
-}