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/src/modes/print-mode.ts

@@ -151,6 +151,10 @@ export async function runPrintMode(runtimeHost: AgentSessionRuntime, options: Pr
 							writeRawStdout(`${content.text}\n`);
 						}
 					}
+					if (assistantMsg.stopReason === "length") {
+						console.error("Response was truncated: the model reached its output token limit.");
+						exitCode = 1;
+					}
 				}
 			}
 		}