feat: get prompt model names (#13607)

fix AI-419

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- New Features
- New API to fetch available models for a prompt, returning default,
optional, and pro models with human‑readable names.
- Added temperature and topP settings to prompt configuration for finer
control.
- Refactor
- When no model is chosen, the default model is used instead of
auto-picking a pro model.
- Model metadata across providers now includes readable names, improving
listings and selection UX.
- Tests
- Updated test snapshots and descriptions to reflect the new
default-model behavior.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

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

@@ -362,6 +362,27 @@ class CopilotPromptType {
   messages!: CopilotPromptMessageType[];
 }
 
+@ObjectType()
+class CopilotModelType {
+  @Field(() => String)
+  id!: string;
+
+  @Field(() => String)
+  name!: string;
+}
+
+@ObjectType()
+export class CopilotModelsType {
+  @Field(() => String)
+  defaultModel!: string;
+
+  @Field(() => [CopilotModelType])
+  optionalModels!: CopilotModelType[];
+
+  @Field(() => [CopilotModelType])
+  proModels!: CopilotModelType[];
+}
+
 @ObjectType()
 export class CopilotSessionType {
   @Field(() => ID)
@@ -400,9 +421,12 @@ export class CopilotType {
 @Throttle()
 @Resolver(() => CopilotType)
 export class CopilotResolver {
+  private readonly modelNames = new Map<string, string>();
+
   constructor(
     private readonly ac: AccessController,
     private readonly mutex: RequestMutex,
+    private readonly prompt: PromptService,
     private readonly chatSession: ChatSessionService,
     private readonly storage: CopilotStorage,
     private readonly docReader: DocReader,
@@ -443,6 +467,48 @@ export class CopilotResolver {
     return { userId: user.id, workspaceId, docId: docId || undefined };
   }
 
+  @ResolveField(() => CopilotModelsType, {
+    description:
+      'List available models for a prompt, with human-readable names',
+    complexity: 2,
+  })
+  async models(
+    @Args('promptName') promptName: string
+  ): Promise<CopilotModelsType> {
+    const prompt = await this.prompt.get(promptName);
+    if (!prompt) {
+      throw new NotFoundException('Prompt not found');
+    }
+    const convertModels = (ids: string[]) => {
+      return ids
+        .map(id => ({ id, name: this.modelNames.get(id) }))
+        .filter(m => !!m.name) as CopilotModelType[];
+    };
+    const proModels = prompt.config?.proModels || [];
+    const missing = new Set(
+      [...prompt.optionalModels, ...proModels].filter(
+        id => !this.modelNames.has(id)
+      )
+    );
+    if (missing.size) {
+      for (const model of missing) {
+        if (this.modelNames.has(model)) continue;
+        const provider = await this.providerFactory.getProviderByModel(model);
+        if (provider?.configured()) {
+          for (const m of provider.models) {
+            if (m.name) this.modelNames.set(m.id, m.name);
+          }
+        }
+      }
+    }
+
+    return {
+      defaultModel: prompt.model,
+      optionalModels: convertModels(prompt.optionalModels),
+      proModels: convertModels(proModels),
+    };
+  }
+
   @ResolveField(() => CopilotSessionType, {
     description: 'Get the session by id',
     complexity: 2,