Add OpenAI's gpt-5.1-chat-latest model (#905)

Author: PeterDaveHello

src/config/index.mjs

@@ -53,6 +53,7 @@ export const chatgptApiModelKeys = [
   'chatgptApi4o_128k',
   'chatgptApi4oLatest',
   'chatgptApi5Latest',
+  'chatgptApi5_1Latest',
   'chatgptApi4oMini',
   'chatgptApi4_8k',
   'chatgptApi4_8k_0613',
@@ -256,6 +257,7 @@ export const Models = {
   },
   chatgptApi4oLatest: { value: 'chatgpt-4o-latest', desc: 'ChatGPT (ChatGPT-4o latest)' },
   chatgptApi5Latest: { value: 'gpt-5-chat-latest', desc: 'ChatGPT (ChatGPT-5 latest)' },
+  chatgptApi5_1Latest: { value: 'gpt-5.1-chat-latest', desc: 'ChatGPT (ChatGPT-5.1 latest)' },
 
   chatgptApi4_1: { value: 'gpt-4.1', desc: 'ChatGPT (GPT-4.1)' },
   chatgptApi4_1_mini: { value: 'gpt-4.1-mini', desc: 'ChatGPT (GPT-4.1 mini)' },