feat(ai): allow /ai models command from console

Remove window type check from cmd_ai_models() so fetching models works
from console. Response is shown via cons_show() when called from console,
or in the AI window when called from there.

src/command/cmd_funcs.c

@@ -11141,12 +11141,7 @@ cmd_ai_models(ProfWin* window, const char* const command, gchar** args)
         cons_show("Use '/ai models %s' to fetch fresh models from the API.", provider_name);
     } else {
         // Default: fetch fresh models from API
-        if (!window || window->type != WIN_AI) {
-            cons_show_error("Must be in an AI chat window to fetch models.");
-            return TRUE;
-        }
-        ProfAiWin* aiwin = (ProfAiWin*)window;
-        ai_fetch_models(provider_name, aiwin);
+        ai_fetch_models(provider_name, window);
     }
 
     return TRUE;