- Replace Message struct with type alias for inference.Message (backward compat)
- Remove convertMessages() — types are now identical via alias
- Extend GenOpts with TopK, TopP, RepeatPenalty (mapped in convertOpts)
- Deprecate StreamingBackend with doc comment (only 2 callers, both in cli/)
- Simplify HTTPTextModel.Chat() — pass messages directly
- Update CLAUDE.md with Backend Architecture section
- Add 2 new tests, remove 1 obsolete test
Co-Authored-By: Virgil <virgil@lethean.io>