Added

• Tag autocomplete support for all clients via Autocomplete trait
• TagSuggestion struct with tag name, label, post count, and category
• Category name mapping (general, artist, copyright, character, meta)

Added

• Rule34 client with API key authentication (Rule34Client)
• Download helper module with progress tracking (Downloader)
• Mock server tests using wiremock for offline testing
• Sort::Random variant for explicit random ordering
• Type-safe ratings per client (compile-time checks)
• Rate limiting with RateLimiter
• Response caching with Cache
• Tag validation with validate_tag()
• Async pagination streams with PostStream
• Retry logic with exponential backoff
• Post trait for generic code across boorus
• Gelbooru API key authentication support
• New error types: Unauthorized, InvalidTag, RateLimited, Io
• ClientBuilder::with_custom_url() for testing with mock servers

Changed

• Rust 2024 edition, MSRV 1.92
• tag() returns Result to check tag limits at build time
• Improved error messages with thiserror

Fixed

• Gelbooru 401 errors now return BooruError::Unauthorized
• Safebooru model now includes file_url, preview_url, sample_url fields