test(coding-agent): fixed think-tool CI failures in gallery and activation tests

- Added a curated think gallery fixture; the generic fallback carries no
  thoughts field, so the streaming state rendered zero lines.
- Seeded the shared test registry with a runtime openai key: the prompt
  preflight validates through the registry, not the per-request getApiKey
  override, so keyless CI runners threw before reaching the mock server.
- Expected reasoning effort "none" — the only disable level the Responses
  wire accepts; "off" is not a wire value.

packages/coding-agent/src/cli/gallery-fixtures/agentic.ts

@@ -361,6 +361,22 @@ export const agenticFixtures: Record<string, GalleryFixture> = {
 		},
 	},
 
+	think: {
+		label: "Think",
+		// Streaming: scratchpad text still arriving.
+		streamingArgs: {
+			thoughts: "The retry loop re-reads the config after every failure — that explains the doubled latency.",
+		},
+		args: {
+			thoughts:
+				"The retry loop re-reads the config after every failure — that explains the doubled latency. Cache the parsed config outside the loop, then re-check the invalidation path before answering.",
+		},
+		result: {
+			content: [{ type: "text", text: "------" }],
+			details: { recorded: true },
+		},
+	},
+
 	hub_jobs: {
 		label: "Hub jobs",
 		renderer: "hub",

packages/coding-agent/test/sdk-tool-activation.test.ts

@@ -269,6 +269,9 @@ describe("createAgentSession defaultInactive tool activation", () => {
 		});
 		const model = getBundledModel("openai", "gpt-5");
 		if (!model) throw new Error("Expected gpt-5 model to exist");
+		// The prompt preflight validates the key through the registry (not the
+		// per-request `getApiKey` override), so seed it for keyless CI runners.
+		modelRegistry.authStorage.setRuntimeApiKey("openai", "test-key");
 		const { session } = await createAgentSession({
 			...baseOptions(tempDir),
 			settings,
@@ -284,7 +287,8 @@ describe("createAgentSession defaultInactive tool activation", () => {
 			expect(requestTexts).toHaveLength(2);
 			expect(JSON.parse(firstRequest)).toEqual(
 				expect.objectContaining({
-					reasoning: { effort: "off" },
+					// "none" is the only disable level the Responses wire accepts ("off" 400s).
+					reasoning: { effort: "none" },
 					tool_choice: expect.objectContaining({ name: "think" }),
 				}),
 			);