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/ai/test/openai-responses-partial-json-cleanup.test.ts

@@ -103,4 +103,30 @@ describe("openai responses partialJson cleanup", () => {
 		expect(toolCallEnd.toolCall).toBe(persistedToolCall);
 		expect("partialJson" in toolCallEnd.toolCall).toBe(false);
 	});
+
+	// #10897
+	it("marks malformed final arguments instead of keeping the parsed prefix", async () => {
+		const model: Model<"openai-responses"> = {
+			id: "gpt-5-mini",
+			name: "GPT-5 Mini",
+			api: "openai-responses",
+			provider: "openai",
+			baseUrl: "https://api.openai.com/v1",
+			reasoning: true,
+			input: ["text"],
+			cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+			contextWindow: 400000,
+			maxTokens: 128000,
+		};
+		const output = createOutput(model);
+		const stream = new AssistantMessageEventStream();
+		const argumentsJson = '{"path":"README.md","content":"updated","mode":.5}';
+
+		await processResponsesStream(createFunctionCallEvents(argumentsJson), output, stream, model);
+
+		const toolCall = output.content[0];
+		if (!toolCall || toolCall.type !== "toolCall") throw new Error("Expected toolCall block");
+		expect(toolCall.arguments).toEqual({});
+		expect(toolCall.argumentsError?.endsWith(`Received arguments:\n${argumentsJson}`)).toBe(true);
+	});
 });