fix(channel): splice替换model_pricing条目 + 增强调试日志

backend/cmd/server/VERSION

@@ -1 +1 @@
-0.1.112
+0.1.105.13

frontend/src/views/admin/ChannelsView.vue

@@ -970,6 +970,7 @@ async function handleSubmit() {
   }
 
   const { group_ids, model_pricing, model_mapping } = formToAPI()
+  console.log('[handleSubmit] model_pricing to send:', JSON.stringify(model_pricing))
 
   submitting.value = true
   try {