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/print-mode.test.ts

@@ -139,4 +139,17 @@ describe("runPrintMode", () => {
 		expect(session.extensionRunner.emit).toHaveBeenCalledTimes(1);
 		expect(session.extensionRunner.emit).toHaveBeenCalledWith({ type: "session_shutdown", reason: "quit" });
 	});
+
+	// #10799
+	it("warns on stderr and returns non-zero when the response was truncated", async () => {
+		const runtimeHost = createRuntimeHost(createAssistantMessage({ stopReason: "length" }));
+		const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+
+		const exitCode = await runPrintMode(runtimeHost as unknown as Parameters<typeof runPrintMode>[0], {
+			mode: "text",
+		});
+
+		expect(exitCode).toBe(1);
+		expect(errorSpy).toHaveBeenCalled();
+	});
 });