feat(core): add optionalModels field in AiPrompt and support the front-end modelId param (#12224)

Close [AI-116](https://linear.app/affine-design/issue/AI-116)

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

- **New Features**
  - Added support for specifying alternative AI models in chat prompts, enabling users to select from multiple available models.
  - Expanded AI model options with new additions: 'gpt-4.1', 'o3', and 'claude-3-5-sonnet-20241022'.

- **Enhancements**
  - Users can now optionally choose a specific AI model during chat interactions.
  - Prompts and chat sessions reflect and support selection of alternative models where applicable.

- **Bug Fixes**
  - Improved handling of prompt configuration defaults for better reliability.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/server/src/plugins/copilot/prompt/chat-prompt.ts

@@ -41,6 +41,7 @@ export class ChatPrompt {
       options.name,
       options.action || undefined,
       options.model,
+      options.optionalModels,
       options.config,
       options.messages
     );
@@ -50,6 +51,7 @@ export class ChatPrompt {
     public readonly name: string,
     public readonly action: string | undefined,
     public readonly model: string,
+    public readonly optionalModels: string[],
     public readonly config: PromptConfig | undefined,
     private readonly messages: PromptMessage[]
   ) {