chore(vendor): import pi 1.3.0

Imported as a linear vendor commit so forge rebases do not replay the upstream root tree.

git-subtree-dir: third_party/pi

git-subtree-split: 71023aec1546d6d677a65669c5665c0927ce0dd0

third_party/pi/packages/durable/test/examples/08-harness-conversations.ts

@@ -0,0 +1,42 @@
+// Conversation handles, typed entries, created conversations, and forks.
+// Run from packages/durable:
+//   node --conditions=source --experimental-strip-types test/examples/08-harness-conversations.ts
+import { BACKGROUND_CONTEXT } from "@earendil-works/chord/context";
+import { createModels } from "@earendil-works/pi-ai/models";
+import { createRegistry, defineEntry, Harness, MemoryStorage } from "../../src/index.ts";
+
+const context = BACKGROUND_CONTEXT;
+const harness = await Harness.open(
+	new MemoryStorage(),
+	{ models: createModels(), registry: createRegistry() },
+	context,
+);
+const root = await harness.root(context);
+await root.configure({ thinkingLevel: "high" }, context);
+
+// Conversation handles are stateless; compare them by id. They bind commits
+// to their conversation. An entry token types an entry kind's `data`.
+const Message = defineEntry<{ from: string }>("message");
+const hello = await root.commit(
+	(tx) =>
+		tx.appendEntry(Message, root.id, {
+			data: { from: "example" },
+			model: [{ role: "user", content: "hello", timestamp: 1 }],
+		}),
+	context,
+);
+console.log("typed entry:", Message.is(hello), hello.data.from);
+
+// createConversation() and fork() apply `agent` and run `init` in the
+// creating commit. A fork starts with the agent the parent had at the fork
+// entry.
+const helper = await harness.createConversation(
+	{ ownership: { kind: "ownerless" }, agent: { thinkingLevel: "minimal" } },
+	context,
+);
+const retry = await root.fork(hello.id, { ownership: { kind: "ownerless" } }, context);
+console.log("helper thinking:", (await helper.agent(context)).thinkingLevel);
+console.log("fork thinking:", (await retry.agent(context)).thinkingLevel);
+console.log("lookup:", (await harness.conversation(retry.id, context))?.id === retry.id);
+
+await harness.close(context);