fix(catalog): omitted forced tool choice for go responses

Applied OpenCode Go DeepSeek tool-choice compat to both OpenAI APIs, so the Responses route drops named selectors while preserving tools.

Added generated-policy and request-payload regression coverage.

Fixes #8243

packages/ai/test/issue-945-repro.test.ts

@@ -1,6 +1,7 @@
 import { describe, expect, it } from "bun:test";
 import { type } from "@oh-my-pi/omptype";
-import { streamOpenAICompletions } from "@oh-my-pi/pi-ai/providers/openai-completions";
+import { type OpenAICompletionsOptions, streamOpenAICompletions } from "@oh-my-pi/pi-ai/providers/openai-completions";
+import { type OpenAIResponsesOptions, streamOpenAIResponses } from "@oh-my-pi/pi-ai/providers/openai-responses";
 import type { Context, Model, Tool } from "@oh-my-pi/pi-ai/types";
 import { getBundledModel } from "@oh-my-pi/pi-catalog/models";
 
@@ -23,7 +24,7 @@ function abortedSignal(): AbortSignal {
 
 async function capturePayload(
 	model: Model<"openai-completions">,
-	opts: Parameters<typeof streamOpenAICompletions>[2],
+	opts: OpenAICompletionsOptions,
 ): Promise<Record<string, unknown>> {
 	const { promise, resolve } = Promise.withResolvers<unknown>();
 	streamOpenAICompletions(model, context, {
@@ -35,12 +36,36 @@ async function capturePayload(
 	return (await promise) as Record<string, unknown>;
 }
 
+async function captureResponsesPayload(
+	model: Model<"openai-responses">,
+	opts: OpenAIResponsesOptions,
+): Promise<Record<string, unknown>> {
+	const { promise, resolve } = Promise.withResolvers<unknown>();
+	streamOpenAIResponses(model, context, {
+		...opts,
+		apiKey: "test-key",
+		signal: abortedSignal(),
+		onPayload: payload => resolve(payload),
+	});
+	return (await promise) as Record<string, unknown>;
+}
+
 describe("OpenCode Go tool_choice compatibility", () => {
 	it("marks deepseek-v4-pro as not supporting tool_choice via compat override", () => {
 		const model = getBundledModel("opencode-go", "deepseek-v4-pro") as Model<"openai-completions">;
 		expect(model.compat?.supportsToolChoice).toBe(false);
 	});
 
+	it("omits forced tool_choice from DeepSeek Flash Responses payloads while preserving tools", async () => {
+		const model = getBundledModel("opencode-go", "deepseek-v4-flash") as Model<"openai-responses">;
+		expect(model.compat.supportsToolChoice).toBe(false);
+		const body = await captureResponsesPayload(model, {
+			toolChoice: { type: "tool", name: "echo" },
+		});
+		expect(body.tools).toEqual([expect.objectContaining({ type: "function", name: "echo" })]);
+		expect(body.tool_choice).toBeUndefined();
+	});
+
 	it("marks mimo-v2.5-pro as not supporting tool_choice via compat override", () => {
 		const model = getBundledModel("opencode-go", "mimo-v2.5-pro") as Model<"openai-completions">;
 		expect(model.compat?.supportsToolChoice).toBe(false);

packages/catalog/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed `opencode-go/deepseek-v4-flash` Responses requests sending forced named `tool_choice` selectors that Console Go rejects while thinking mode is active.
+
 ## [17.2.12] - 2026-08-08
 
 ### Fixed

packages/catalog/scripts/generated-policies.ts

@@ -391,7 +391,7 @@ function applyGeneratedModelPolicy(model: ModelSpec<Api>): void {
 		};
 	}
 	if (
-		model.api === "openai-completions" &&
+		(model.api === "openai-completions" || model.api === "openai-responses") &&
 		model.provider === "opencode-go" &&
 		(model.id === "deepseek-v4-flash" || model.id === "deepseek-v4-pro")
 	) {

packages/catalog/test/generated-policies.test.ts

@@ -319,11 +319,11 @@ describe("generated model policies", () => {
 		expect(models[0]?.compat?.supportsToolChoice).toBe(false);
 	});
 
-	it("sets OpenCode Go DeepSeek V4 tool-call request compat", () => {
-		const models: ModelSpec<"openai-completions">[] = [
+	it("sets OpenCode Go DeepSeek V4 tool-call request compat for both OpenAI APIs", () => {
+		const models: ModelSpec<Api>[] = [
 			createSpec({
 				id: "deepseek-v4-flash",
-				api: "openai-completions",
+				api: "openai-responses",
 				provider: "opencode-go",
 			}),
 			createSpec({