Rondine v0.1.1

• Add platform-specific engine installation guidance when no runnable engine is detected
• Make rondine setup automatically select and verify engines compatible with the host
• Refuse to start rondine serve when the selected engine is missing or incompatible
• Detect Rondine-managed llama.cpp, MLX-LM, and vLLM installations
• Improve setup error reporting and document the engine installation workflow