fix(agent): recover completed tools after stream read errors

packages/coding-agent/test/agent-session-retry-cap.test.ts

@@ -141,6 +141,66 @@ describe("AgentSession retry delay cap", () => {
 		expect(session.isRetrying).toBe(false);
 	});
 
+	it("auto-retries OpenAI Responses stream_read_error instead of stopping the conversation", async () => {
+		const model = getBundledModel("openai", "gpt-5");
+		if (!model) {
+			throw new Error("Expected bundled OpenAI test model to exist");
+		}
+		authStorage.setRuntimeApiKey("openai", "openai-test-key");
+
+		const mock = createMockModel({
+			responses: [
+				{ throw: "Error Code stream_read_error: stream_read_error" },
+				{ content: ["recovered after stream read retry"], stopReason: "stop" },
+			],
+		});
+		const agent = new Agent({
+			getApiKey: requestedModel => `${requestedModel.provider}-test-key`,
+			initialState: {
+				model,
+				systemPrompt: ["Test"],
+				tools: [],
+				messages: [],
+			},
+			streamFn: (requestedModel, context, options) => mock.stream(requestedModel, context, options),
+		});
+
+		const settings = Settings.isolated({
+			"compaction.enabled": false,
+			"retry.baseDelayMs": 5,
+			"retry.maxDelayMs": 5_000,
+			"retry.maxRetries": 1,
+			"retry.modelFallback": false,
+		});
+		settings.setModelRole("default", `${model.provider}/${model.id}`);
+
+		session = new AgentSession({
+			agent,
+			sessionManager: SessionManager.inMemory(),
+			settings,
+			modelRegistry,
+		});
+
+		vi.spyOn(scheduler, "wait").mockResolvedValue(undefined);
+		const retryStartEvents: AutoRetryStartEvent[] = [];
+		const retryEndEvents: AutoRetryEndEvent[] = [];
+		session.subscribe(event => {
+			if (event.type === "auto_retry_start") retryStartEvents.push(event);
+			if (event.type === "auto_retry_end") retryEndEvents.push(event);
+		});
+
+		await session.prompt("Trigger stream read retry");
+		await session.waitForIdle();
+
+		expect(mock.calls).toHaveLength(2);
+		expect(retryStartEvents).toHaveLength(1);
+		expect(retryEndEvents).toHaveLength(1);
+		expect(retryEndEvents[0]).toMatchObject({ success: true });
+		const last = lastAssistant(session);
+		expect(last.stopReason).toBe("stop");
+		expect(last.content).toContainEqual({ type: "text", text: "recovered after stream read retry" });
+	});
+
 	it("switches credentials instead of failing the delay cap for account rate limits", async () => {
 		const model = getBundledModel("anthropic", "claude-sonnet-4-5");
 		if (!model) {