Add user-friendly loading feedback for all AI/long-running operations

- Discovery: show '搜索中约需30-60秒' message, auto-save to history, timeout hint
- Discovery extract/outreach: show '正在分析网站/生成文案' loading message
- Translate: inline '翻译中...' placeholder while waiting
- Marketing: inline 'AI 生成中...' placeholder, success feedback
- Quotations AI: inline progress text + ElMessage.info during generation
- Analytics: add v-loading skeleton with '加载数据分析中...'
- Notifications: add v-loading skeleton with '加载通知中...'
- Followup: wire up '扫描跟进提醒' button with AI progress indicator

user-frontend/src/views/Translate.vue

@@ -70,30 +70,43 @@ const extractResult = ref('')
 async function doTranslate() {
   if (!form.value.text.trim()) return
   loading.value = true
+  result.value = '翻译中...'
   try {
     const res = await translate(form.value)
     result.value = res.data?.translated_text || res.translated_text || ''
-  } catch { ElMessage.error('翻译失败') }
+  } catch {
+    result.value = ''
+    ElMessage.error('翻译失败')
+  }
   finally { loading.value = false }
 }
 
 async function getReply() {
   if (!replyInquiry.value.trim()) return
   replyLoading.value = true
+  suggestions.value = [{ content: '生成中...', tone: '处理中' }]
   try {
     const res = await translateReply({ text: replyInquiry.value })
     suggestions.value = res.data?.suggestions || res.suggestions || []
-  } catch { ElMessage.error('生成建议失败') }
+    if (!suggestions.length) ElMessage.info('未生成建议，请尝试修改询盘内容')
+  } catch {
+    suggestions.value = []
+    ElMessage.error('生成建议失败')
+  }
   finally { replyLoading.value = false }
 }
 
 async function doExtract() {
   if (!extractText.value.trim()) return
   extractLoading.value = true
+  extractResult.value = '提取中...'
   try {
     const res = await extractInfo({ text: extractText.value })
     extractResult.value = JSON.stringify(res.data || res, null, 2)
-  } catch { ElMessage.error('提取失败') }
+  } catch {
+    extractResult.value = ''
+    ElMessage.error('提取失败')
+  }
   finally { extractLoading.value = false }
 }