Fix [TypesScript] [LLM Api] Chaining Model

- [+] fix(api.ts): make provider property optional in LLMModel interface

app/client/api.ts

@@ -46,7 +46,7 @@ export interface LLMUsage {
 export interface LLMModel {
   name: string;
   available: boolean;
-  provider: LLMModelProvider;
+  provider?: LLMModelProvider;
 }
 
 export interface LLMModelProvider {