- Remove sync.RWMutex and rrCounters from Config struct
- Simplify GetModelConfig to use global atomic counter for load balancing
- Remove unnecessary locks from HasProvidersConfig, SaveConfig, etc.
- Add buildModelWithProtocol helper to handle models with existing prefix
- Fix TestCreateProviderReturnsHTTPProviderForOpenRouter to use model_list
- Upgrade all Claude 3 references to Claude 4 across documentation
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>