refactor(pi): split the Pi harness into runtime and UI

src/bundled/pi/index.test.ts

@@ -0,0 +1,23 @@
+// @vitest-environment jsdom
+import { expect, it, vi } from "vitest";
+import { appliedType } from "../../features/agents/plugin-testing";
+import * as pi from "./index";
+
+vi.mock("@tauri-apps/api/core", () => ({ isTauri: () => true }));
+
+it("shows the Pi type's screens from the runtime its agent entry registers", () => {
+  // The UI needs no host; only the runtime starts Pi.
+  expect(pi.inject).toEqual(["agents"]);
+  expect(pi.agent.inject).toEqual(["agents", "host"]);
+  const type = appliedType(pi, {
+    pluginOwner: { id: "buzz.pi", revision: "r1" },
+    host: { request: vi.fn() },
+    agents: { relay: () => undefined },
+    effect: vi.fn(),
+  });
+  expect(type).toMatchObject({ id: "pi", title: "Pi", timeoutMs: 120_000 });
+  expect(type?.Create).toBeTypeOf("function");
+  expect(type?.CreateModel).toBeTypeOf("function");
+  expect(type?.icon).toBeDefined();
+  expect(type?.tabs?.map((tab) => tab.id)).toEqual(["settings", "activity"]);
+});

src/bundled/pi/index.ts

@@ -16,9 +16,45 @@ export const TYPE_ID = "pi";
  * which includes the first install of Pi's packages. */
 const HANDOVER_MS = 2 * 60_000;
 
-export const inject = ["agents", "host"];
+/** What the type's UI reaches of its runtime. */
+type PiExposed = Parameters<typeof createTabs>[0];
+
+export const inject = ["agents"];
 export const apply: PluginModule["apply"] = (ctx) => {
   // Only the desktop app can start the Pi host; no unusable type elsewhere.
+  if (!isTauri()) return;
+  ctx.agents.present<PiExposed, Config>(TYPE_ID, (exposed) => {
+    const { ActivityTab, Create, CreateModel, SettingsTab } =
+      createTabs(exposed);
+    return {
+      icon: PiLogoIcon,
+      Create,
+      CreateModel,
+      tabs: [
+        {
+          id: "settings",
+          title: "Settings",
+          role: "settings",
+          splitSettings: true,
+          component: SettingsTab,
+        },
+        {
+          id: "activity",
+          title: "Activity",
+          role: "activity",
+          component: ActivityTab,
+        },
+      ],
+    };
+  });
+};
+
+// The runtime, which runs where the agents do.
+export const agent: NonNullable<PluginModule["agent"]> = {
+  inject: ["agents", "host"],
+  apply: (ctx) => applyAgent(ctx),
+};
+function applyAgent(ctx: Parameters<PluginModule["apply"]>[0]) {
   if (!isTauri()) return;
   const { agents, host } = ctx;
   const typeKey = `${ctx.pluginOwner?.id ?? "buzz.pi"}/${TYPE_ID}`;
@@ -30,10 +66,6 @@ export const apply: PluginModule["apply"] = (ctx) => {
     repositoriesContext,
     (key) => agents.handle(key),
   );
-  const { ActivityTab, Create, CreateModel, SettingsTab } = createTabs({
-    setup: runtime.setup,
-    runtime,
-  });
   const sync = () => {
     const snapshot = agents.snapshot();
     if (snapshot.status === "loading") return;
@@ -51,12 +83,10 @@ export const apply: PluginModule["apply"] = (ctx) => {
   agents.register<Config>({
     id: TYPE_ID,
     title: "Pi",
-    icon: PiLogoIcon,
     description:
       "Pi on this computer, with any provider Pi supports. Each thread it is mentioned in is one continuing conversation.",
     defaults: () => ({ config: DEFAULT_CONFIG }),
-    Create,
-    CreateModel,
+    expose: { setup: runtime.setup, runtime } satisfies PiExposed,
     adopt: (carry, saved) => ({
       ...saved,
       instructions: carry.instructions ?? saved.instructions,
@@ -81,21 +111,6 @@ export const apply: PluginModule["apply"] = (ctx) => {
       list: (key) => runtime.sessions(key),
       subscribe: (listener) => runtime.subscribe(listener),
     },
-    tabs: [
-      {
-        id: "settings",
-        title: "Settings",
-        role: "settings",
-        splitSettings: true,
-        component: SettingsTab,
-      },
-      {
-        id: "activity",
-        title: "Activity",
-        role: "activity",
-        component: ActivityTab,
-      },
-    ],
     sessionControls: {
       scope: (agent) => config(agent.config).scope,
       state: (agent, place) => runtime.sessionState(agent, place),
@@ -107,4 +122,4 @@ export const apply: PluginModule["apply"] = (ctx) => {
     runOnce: (turn) => runtime.runOnce(turn),
     timeoutMs: HANDOVER_MS,
   });
-};
+}

src/bundled/pi/tabs.tsx

@@ -182,7 +182,7 @@ export function createTabs({
   setup,
   runtime,
 }: Readonly<{
-  setup: PiSetup;
+  setup: Pick<PiSetup, "providers" | "models" | "login" | "test">;
   runtime: Pick<PiRuntime, "places" | "working" | "transcript" | "subscribe">;
 }>) {
   /** The provider, its key and its model, and a test that they answer. As