//! Extension runner over native extension instances.
//!
//! | Module | Contents |
//! |---|---|
//! | [`api`] | instance contract, registrations, call context |
//! | [`deadline`] | handler deadlines that pause while a dialog is open |
//! | [`host`] | [`host::HostApi`], [`host::HostOp`]: what extensions can do |
//! | [`runner`] | registries and composition dispatch |
//! | [`settings`] | extension settings registry: schema, layered values, secret fields, writes, change events |
//! | [`sources`] | shared source discovery (share dir, agent, project, `-e`) and the docs root (dist.md ยง5) |
//! | [`tool`] | extension tools as `AgentTool`s |