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/coding-agent/test/sdk-session-manager.test.ts

@@ -78,7 +78,7 @@ describe("createAgentSession session manager defaults", () => {
 		});
 
 		expect(session.sessionManager).toBe(sessionManager);
-		expect(session.systemPrompt).toContain(`Current working directory: ${sessionCwd}`);
+		expect(session.systemPrompt).toContain(`<cwd>\n${sessionCwd}\n</cwd>`);
 
 		const bashTool = session.agent.state.tools.find((tool) => tool.name === "bash");
 		expect(bashTool).toBeTruthy();