feat(server): improve session modify (#12928)

fix AI-248

packages/backend/server/src/plugins/copilot/resolver.ts

@@ -39,15 +39,12 @@ import { PromptMessage, StreamObject } from './providers';
 import { ChatSessionService } from './session';
 import { CopilotStorage } from './storage';
 import {
-  AvailableModels,
   type ChatHistory,
   type ChatMessage,
   type ChatSessionState,
   SubmittedMessage,
 } from './types';
 
-registerEnumType(AvailableModels, { name: 'CopilotModel' });
-
 export const COPILOT_LOCKER = 'copilot';
 
 // ================== Input Types ==================
@@ -301,8 +298,6 @@ class CopilotPromptMessageType {
   params!: Record<string, string> | null;
 }
 
-registerEnumType(AvailableModels, { name: 'CopilotModels' });
-
 @ObjectType()
 class CopilotPromptType {
   @Field(() => String)
@@ -533,7 +528,7 @@ export class CopilotResolver {
     }
 
     await this.chatSession.checkQuota(user.id);
-    return await this.chatSession.updateSession({
+    return await this.chatSession.update({
       ...options,
       userId: user.id,
     });
@@ -682,8 +677,8 @@ class CreateCopilotPromptInput {
   @Field(() => String)
   name!: string;
 
-  @Field(() => AvailableModels)
-  model!: AvailableModels;
+  @Field(() => String)
+  model!: string;
 
   @Field(() => String, { nullable: true })
   action!: string | null;