refactor: ensure default model remains chosen after page switch

Author: sudoleg

config.json

@@ -16,12 +16,12 @@
             "text-embedding-ada-002"
         ],
         "gpts": [
+            "gpt-4.1-nano",
             "gpt-5.1-chat-latest",
             "gpt-5.1",
             "gpt-5-nano",
             "gpt-5-mini",
             "gpt-5",
-            "gpt-4.1-nano",
             "gpt-4.1-mini",
             "gpt-4.1",
             "gpt-4o-mini",