fix(ai-providers): gate Claude models input and refine excluded tag styles

src/pages/AiProvidersPage.module.scss

@@ -404,8 +404,17 @@
   }
 
   .excludedModelTag {
-    background: rgba(251, 191, 36, 0.2);
-    border-color: rgba(251, 191, 36, 0.4);
+    background: rgba(251, 191, 36, 0.22);
+    border-color: rgba(251, 191, 36, 0.55);
+    color: #fde68a;
+
+    .modelName {
+      color: #fde68a;
+    }
+  }
+
+  .excludedModelsLabel {
+    color: #fde68a;
   }
 
   .apiKeyEntryCard {

src/pages/AiProvidersPage.tsx

@@ -1897,6 +1897,7 @@ export function AiProvidersPage() {
             keyPlaceholder={t('common.custom_headers_key_placeholder')}
             valuePlaceholder={t('common.custom_headers_value_placeholder')}
           />
+          {modal?.type === 'claude' && (
             <div className="form-group">
               <label>{t('ai_providers.claude_models_label')}</label>
               <ModelInputList
@@ -1910,6 +1911,7 @@ export function AiProvidersPage() {
                 disabled={saving}
               />
             </div>
+          )}
           <div className="form-group">
             <label>{t('ai_providers.excluded_models_label')}</label>
             <textarea