(openai responses): add string to type for models (#1068)

Author: tinalenguyen

.changeset/fluffy-phones-sort.md

@@ -0,0 +1,5 @@
+---
+'@livekit/agents-plugin-openai': patch
+---
+
+supports string inputs for model parameter

plugins/openai/src/responses/llm.ts

@@ -14,7 +14,7 @@ import OpenAI from 'openai';
 import type { ChatModels } from '../models.js';
 
 interface LLMOptions {
-  model: ChatModels;
+  model: string | ChatModels;
   apiKey?: string;
   baseURL?: string;
   client?: OpenAI;
@@ -140,7 +140,7 @@ export class LLMStream extends llm.LLMStream {
       modelOptions,
       strictToolSchema,
     }: {
-      model: ChatModels;
+      model: string | ChatModels;
       client: OpenAI;
       chatCtx: llm.ChatContext;
       toolCtx?: llm.ToolContext;