Revert "Fix [TypesScript] [LLM Api] Chaining Model"

This reverts commit 8ca525dc7adce7860bc79ac8dfe54ab0e896a4ab.

Reason: It's suddenly stopped lmao

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 {