Further fixes to tests
Pass O3 simulation test when keys are not set, along with a notice
Updated docs on testing, simulation tests / contributing
Support for OpenAI o4-mini and o4-mini-high
- Added autouse fixture to mock provider availability in tests
- Updated test expectations to match new auto mode behavior
- Fixed mock provider capabilities to return proper values
- Updated claude continuation tests to set default model
- All 256 tests now passing
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
