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

frontend/packages/swarm-ui/test/create-agent-archetype.test.mjs

@@ -0,0 +1,67 @@
+// The create-agent form's archetype picker: what a pick puts in the form.
+// Run by `npm test` with Node's type stripping.
+import assert from "node:assert/strict";
+import { test } from "node:test";
+import { archetypeKey, prefill } from "../src/pages/CreateAgentArchetype.ts";
+
+const defaults = ["messaging", "meta", "inbox", "execution"];
+
+const empty = {
+  permissions: defaults,
+  cpu: "",
+  memory: "",
+  inference: { model: "", effort: "", subagents: "", maxSubagents: "" },
+};
+
+test("no archetype is the default permissions and empty settings", () => {
+  assert.deepEqual(prefill(undefined, defaults), empty);
+});
+
+test("an archetype's settings fill the form", () => {
+  const reviewer = {
+    source: "hyperhive",
+    name: "reviewer",
+    description: "reviews",
+    permissions: ["messaging", "meta", "inbox"],
+    limits: { cpu_quota: "200%", memory_max: "4G" },
+    inference: {
+      model: "opus",
+      effort: "high",
+      subagent_models: ["haiku", "sonnet"],
+      max_subagents: 0,
+    },
+  };
+  assert.deepEqual(prefill(reviewer, defaults), {
+    permissions: ["messaging", "meta", "inbox"],
+    cpu: "200%",
+    memory: "4G",
+    inference: {
+      model: "opus",
+      effort: "high",
+      subagents: "haiku, sonnet",
+      maxSubagents: "0",
+    },
+  });
+});
+
+test("an archetype that sets nothing leaves the form as no archetype does", () => {
+  const bare = { source: "hyperhive", name: "bare", description: "d" };
+  assert.deepEqual(prefill(bare, defaults), empty);
+});
+
+test("an empty permission list is kept, not replaced by the default", () => {
+  const none = {
+    source: "hyperhive",
+    name: "none",
+    description: "d",
+    permissions: [],
+  };
+  assert.deepEqual(prefill(none, defaults).permissions, []);
+});
+
+test("the key tells sources apart", () => {
+  assert.notEqual(
+    archetypeKey({ source: "a", name: "x", description: "" }),
+    archetypeKey({ source: "b", name: "x", description: "" }),
+  );
+});