Description

Add helper utilities to make encryption easier to use throughout the application.

Tasks

• Create lib/crypto-utils.ts with:
  • generateShareableUrl(id: string, key: CryptoKey) - Create shareable URL
  • extractKeyFromUrl(url: string) - Extract key from URL fragment
  • encryptGist(files: FileData[], key?: CryptoKey) - High-level encryption
  • decryptGist(data: Uint8Array, key: CryptoKey) - High-level decryption
• Add TypeScript types for encrypted data
• Create usage examples
• Add unit tests

Acceptance Criteria

• Simple API for common operations
• Type-safe implementations
• Good documentation
• Handles edge cases gracefully