v0.4.0 - API Stability Improvements

Major Breaking Changes

This release introduces significant API improvements for long-term stability:

Private Fields with Getters

All public struct fields are now private with getter methods following Rust API Guidelines (C-STRUCT-PRIVATE):

• AgentOptions: Use .model(), .temperature(), etc. instead of direct field access
• Tool: Use .name(), .description(), .input_schema()
• HookDecision: Use .continue_execution(), .modified_input(), etc.

Error Handling Improvements

• Client::new() now returns Result<Self> instead of panicking
• add_tool_result() now returns Result<()> for proper error propagation

New Features

• Client::interrupt_handle(): Thread-safe cancellation handle
• Input Validation: Temperature range, URL format, model name validation
• Newtype Wrappers: Optional ModelName, BaseUrl, Temperature types for compile-time safety

Bug Fixes

• Fixed HTTP client panics on invalid configuration
• Fixed silent error suppressions in error responses
• Fixed SSE parsing for empty chunks/heartbeats
• Improved schema validation with defensive assertions

Documentation

• Added comprehensive migration guide in CHANGELOG.md
• Updated 150+ doctests for new APIs
• Added SAFETY comments to unsafe blocks
• 97% doctest success rate (135/139 passing)

Migration Guide

See CHANGELOG.md for detailed migration instructions.

Stats

• 66 unit tests passing
• 138 doctests passing
• Zero clippy warnings
• Rust 1.85+ required (Edition 2024)

Full Changelog: v0.3.0...v0.4.0