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/29-sandbox-per-conversation.ts

@@ -0,0 +1,82 @@
+// One sandbox per conversation: the app records each conversation's sandbox in its own document, and the Harness
+// environment function looks it up for every tool call. Here a sandbox is a directory; a hosted product would return
+// an ExecutionEnv that runs inside the conversation's container.
+// Run from packages/durable:
+//   node --conditions=source --experimental-strip-types test/examples/29-sandbox-per-conversation.ts
+import { mkdtemp, readFile, rm } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { BACKGROUND_CONTEXT } from "@earendil-works/chord/context";
+import { createModels } from "@earendil-works/pi-ai/models";
+import { fauxAssistantMessage, fauxProvider, fauxToolCall } from "@earendil-works/pi-ai/providers/faux";
+import { NodeExecutionEnv } from "../../src/env/node.ts";
+import { createRegistry, defineDoc, Harness, MemoryStorage } from "../../src/index.ts";
+import { CodingTools } from "../../src/tools/index.ts";
+
+const context = BACKGROUND_CONTEXT;
+
+// Which sandbox a conversation runs in. `fork: "initial"`: a fork gets no sandbox until the app assigns one.
+const Sandbox = defineDoc<{ path?: string }>({
+	kind: "app.sandbox",
+	version: 1,
+	scope: "conversation",
+	history: "latest",
+	fork: "initial",
+	initial: () => ({}),
+});
+
+const faux = fauxProvider();
+const models = createModels();
+models.setProvider(faux.provider);
+const note = (text: string) =>
+	fauxAssistantMessage(fauxToolCall("write", { path: "note.txt", content: text }), { stopReason: "toolUse" });
+faux.setResponses([
+	note("from alice"),
+	fauxAssistantMessage("Saved."),
+	note("from bob"),
+	fauxAssistantMessage("Saved."),
+]);
+
+const registry = createRegistry();
+registry.install(CodingTools);
+const harness = await Harness.open(
+	new MemoryStorage(),
+	{
+		models,
+		registry,
+		// Committed reads only; a conversation without a sandbox gets no environment, so its tools fail cleanly.
+		env: async ({ conversationId, read }, envContext) => {
+			const sandbox = await read.snapshot(Sandbox, conversationId, envContext);
+			return sandbox?.path === undefined ? undefined : new NodeExecutionEnv({ cwd: sandbox.path });
+		},
+	},
+	context,
+);
+
+// Each user's conversation gets a fresh sandbox in the creating commit.
+const model = { provider: "faux", modelId: "faux-1" };
+async function conversationFor(user: string) {
+	const path = await mkdtemp(join(tmpdir(), `pi-durable-sandbox-${user}-`));
+	const conversation = await harness.createConversation(
+		{
+			ownership: { kind: "ownerless" },
+			agent: { model },
+			init: async (tx, id) => {
+				(await tx.doc(Sandbox, id)).path = path;
+			},
+		},
+		context,
+	);
+	return { conversation, path };
+}
+
+const alice = await conversationFor("alice");
+const bob = await conversationFor("bob");
+await (await alice.conversation.submit({ type: "input", content: "Leave a note." }, context)).wait(context);
+await (await bob.conversation.submit({ type: "input", content: "Leave a note." }, context)).wait(context);
+console.log("alice's sandbox:", await readFile(join(alice.path, "note.txt"), "utf8"));
+console.log("bob's sandbox:", await readFile(join(bob.path, "note.txt"), "utf8"));
+
+await harness.close(context);
+await rm(alice.path, { recursive: true, force: true });
+await rm(bob.path, { recursive: true, force: true });