- Add InProcessServer field to MCPServerConfig (json:"-", never serialized)
- Add "inprocess" transport type to config, validation, and connection pool
- Add createInProcessClient() using mcp-go client.NewInProcessClient()
- Add Kit.AddInProcessMCPServer() convenience method
- Add Options.InProcessMCPServers for init-time registration
- Export MCPServer type alias (= server.MCPServer) in pkg/kit/types.go
- Add 8 tests covering config, pool, tool manager, and edge cases
- Update SDK README, kit-sdk skill, and www docs