Add reasoning toggle for Grok 4 models

Author: chrarnoldus

src/lib/providers/model-settings.ts

@@ -72,6 +72,12 @@ export function getModelVariants(model: string): OpenCodeSettings['variants'] {
       high: { reasoning: { enabled: true, effort: 'high' } },
     };
   }
+  if (model.startsWith('x-ai/grok-4')) {
+    return {
+      'non-reasoning': { reasoning: { enabled: false } },
+      reasoning: { reasoning: { enabled: true } },
+    };
+  }
   return undefined;
 }