Semantic operations, handlers, and provider activity

A RhoOperation states what a conversation may do. A handler binds that semantic request to a concrete implementation for the selected model. Bindings record both the handler and the reason it was selected; request translators turn bindings into provider wire values while encoding a request.

Details

Provider-hosted activity is normalized as Content, never as a local ToolCall. The agent can therefore retain and report a web search without placing it in its executable tool registry.