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/07-configuration.ts

@@ -0,0 +1,99 @@
+// Per-conversation agent choices and Harness-wide settings.
+// Run from packages/durable:
+//   node --conditions=source --experimental-strip-types test/examples/07-configuration.ts
+import { BACKGROUND_CONTEXT } from "@earendil-works/chord/context";
+import { Type } from "@earendil-works/pi-ai";
+import { createModels } from "@earendil-works/pi-ai/models";
+import {
+	AgentDoc,
+	createRegistry,
+	defineExtension,
+	defineTool,
+	Harness,
+	type HarnessSettings,
+	MemoryStorage,
+	section,
+	type ToolRegistration,
+} from "../../src/index.ts";
+
+const context = BACKGROUND_CONTEXT;
+
+// Apps may attach their own metadata to tools, such as a prompt snippet.
+type AppTool = ToolRegistration & { readonly snippet?: string };
+
+function exampleTool(name: string, description: string): AppTool {
+	const tool = defineTool({
+		name,
+		description,
+		parameters: Type.Object({ path: Type.String() }),
+		execute: async (args) => ({ output: [{ type: "text", text: `${name} ${args.path}` }] }),
+	});
+	return { ...tool, snippet: `Use ${name} for files.` };
+}
+
+const read = exampleTool("read", "Read a file");
+const write = exampleTool("write", "Write a file");
+const grep = exampleTool("grep", "Search files");
+const Files = defineExtension<AppTool>({ name: "files", tools: [read, write] });
+const Search = defineExtension<AppTool>({ name: "search", tools: [grep] });
+// Sections see the offered tools as app tools, so one can render their snippets.
+const Snippets = defineExtension<AppTool>({
+	name: "snippets",
+	sections: [section("tool_snippets", (input) => input.agent.tools.map((tool) => tool.snippet).join("\n"))],
+});
+
+const registry = createRegistry<AppTool>();
+registry.install(Files);
+registry.install(Search);
+registry.install(Snippets);
+
+// Settings are Harness-wide run policy, read at every use and never stored.
+// A getter makes a value live, such as one backed by the app's settings file.
+let timeoutMs = 60_000;
+const settings: HarnessSettings = {
+	get stream() {
+		return { timeoutMs };
+	},
+	retry: { maxRetries: 5 },
+	toolExecution: "sequential",
+};
+const harness = await Harness.open(new MemoryStorage(), { models: createModels(), registry, settings }, context);
+const root = await harness.root(context);
+
+// A new conversation stores no choices and follows the host: every installed
+// extension, all of their tools.
+const tools = async () => (await root.agent(context)).tools.map((tool) => tool.name);
+console.log("default tools:", await tools());
+
+// configure() stores choices in the conversation's pi.agent document, one
+// commit per call. Extensions and tools are passed as objects and stored by
+// name, so a typo cannot slip in.
+await root.configure(
+	{
+		model: { provider: "anthropic", modelId: "claude-sonnet-4-5" },
+		thinkingLevel: "high",
+		tools: [write, read],
+	},
+	context,
+);
+console.log("stored:", await harness.snapshot(AgentDoc, root.id, context));
+const agent = await root.agent(context);
+console.log("model:", agent.model, "thinking:", agent.thinkingLevel, "tools:", await tools());
+
+// Deselect an extension; `null` clears a stored field back to the host default.
+await root.configure({ extensions: { remove: [Search] }, tools: null }, context);
+console.log("without search:", await tools());
+
+// Stored names outlive the code. The conversation selects exactly these two
+// extensions; uninstalling "files" leaves it selected, and requests just stop
+// offering its tools until it is back.
+await root.configure({ extensions: [Files, Search] }, context);
+registry.uninstall(Files);
+console.log("files uninstalled:", await tools());
+registry.install(Files);
+console.log("files reinstalled:", await tools());
+
+// Settings changes need no commit; the next request uses the new timeout.
+timeoutMs = 120_000;
+
+await harness.close(context);