archetypes: prefill the create form from flake-declared agent archetypes

A flake declares agent archetypes in its `hyperhiveArchetypes` output,
`<name> = { module; meta; }`. The hyperhive flake ships `reviewer`
(default permissions without `execution`).

swarm-builder answers `$SWARM.builder.archetypes` with the `meta` of
every archetype its own hyperhive source declares. swarm-controller asks
once the queue connects and every 10 minutes, checks each archetype as
`POST /api/agents` checks its settings, and stores the result in the
`agent-archetypes` KV bucket when it changed. `GET /api/archetypes`
serves it, and the create form's archetype select prefills permissions,
resource caps and inference from it.

The agent created is an ordinary agent with its own config repo; the
archetype's module is not applied yet.

Refs #5386

swarm-queue-client/src/lib.rs

@@ -231,6 +231,11 @@ pub mod agent_permissions;
 /// on [`agent_state_subject`] only.
 pub mod agent_login;
 
+/// The bucket swarm-controller keeps the evaluated agent archetypes in — one
+/// key per source flake. The names and the stored type are unconditional;
+/// opening needs `kv`.
+pub mod archetypes;
+
 #[cfg(feature = "kv")]
 mod kv;