Enhance token refresh functionality across multiple executors

- Updated refreshCredentials methods in various executors (Antigravity, Base, Default, Github, Kiro) to accept optional proxyOptions for improved proxy handling.
- Modified token refresh logic to utilize proxy-aware fetch for better network management.
- Enhanced usage retrieval functions to support proxy options, ensuring seamless integration with proxy configurations.
- Updated ModelSelectModal and ProviderInfoCard components to incorporate kind filtering for improved user experience in model selection.
- Added validation for API keys in the provider validation route, including support for webSearch/webFetch providers.

src/app/(dashboard)/dashboard/combos/page.js

@@ -339,7 +339,7 @@ function ModelItem({ index, model, isFirst, isLast, onEdit, onMoveUp, onMoveDown
   );
 }
 
-function ComboFormModal({ isOpen, combo, onClose, onSave, activeProviders }) {
+function ComboFormModal({ isOpen, combo, onClose, onSave, activeProviders, kindFilter = null }) {
   // Initialize state with combo values - key prop on parent handles reset on remount
   const [name, setName] = useState(combo?.name || "");
   const [models, setModels] = useState(combo?.models || []);
@@ -504,6 +504,7 @@ function ComboFormModal({ isOpen, combo, onClose, onSave, activeProviders }) {
         activeProviders={activeProviders}
         modelAliases={modelAliases}
         title="Add Model to Combo"
+        kindFilter={kindFilter}
       />
     </>
   );