- Extract error handling, path validation, and handlers into separate modules
- Add CacheCheckResult to pre-fetch metadata and avoid double lookups
- Deprecate legacy cache methods in favor of optimized alternatives
- Enable tokio fs feature for async file operations
- Remove debug profile from release build
- Switch from sha2 crate to blake3 for faster hashing (4-7x speedup)
- Use Blake3's built-in to_hex() instead of separate hex crate
- Remove hex and sha2 dependencies
- Eliminates 40% CPU bottleneck in generate_cache_key()
