feat: remove redundant error notifications in prompt loading

Removed duplicate message.error calls in both PromptSelector.vue and Forecast.vue components after logging errors to console. The error messages were being displayed twice to users, creating a redundant UX. Now errors are only logged to console for debugging while maintaining clean user interface.

frontend/app/web-gold/src/components/PromptSelector.vue

@@ -234,7 +234,6 @@ async function loadUserPrompts() {
     await restoreSelectedPromptId()
   } catch (error) {
     console.error('加载提示词失败:', error)
-    message.error('加载提示词失败')
   }
 }
 

frontend/app/web-gold/src/views/trends/Forecast.vue

@@ -92,7 +92,6 @@ async function loadUserPrompts() {
     }
   } catch (error) {
     console.error('加载提示词失败:', error)
-    message.error('加载提示词失败')
   } finally {
     loadingPrompts.value = false
   }