Add ReAct and OpenHands agents, WebSearch and CodeInterpreter tools,
full MCP protocol layer (server/client/transport), Gemini cloud engine
support, 12 new model specs (4 local MoE + 8 cloud), trace system,
and comprehensive test coverage across all dimensions (hardware, engine,
memory, agents, tools, MCP, integration).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>