Require Grok 4.6 in the xAI OAuth model catalog

Failing expectation for the OAuth default model list so the catalog
can pick up Grok 4.6 while keeping grok-4.5 as the session default.

CL-5933

Author: TheGreatAxios

src/config/xai-providers.test.ts

@@ -12,9 +12,10 @@ import {
 } from "./xai-providers.js";
 
 describe("xAI OAuth provider projection", () => {
-  test("default models mirror grok CLI catalog", () => {
-    expect([...XAI_DEFAULT_MODELS]).toEqual(["grok-4.5", "grok-composer-2.5-fast"]);
-    expect(XAI_DEFAULT_MODELS[0]).toBe("grok-4.5");
+  test("default models include Grok 4.6 while defaulting to the CLI coding model", () => {
+    const models: string[] = [...XAI_DEFAULT_MODELS];
+    expect(models).toEqual(["grok-4.5", "grok-4.6", "grok-composer-2.5-fast"]);
+    expect(models[0]).toBe("grok-4.5");
   });
 
   const profile: XaiProfile = {