feat: 商机跟单默认筛选跟进中 + 已流失置底 + 清空列收

- 后端: 状态改为已流失时自动清空 expected_revenue_date
- PC端: 默认筛选跟进中，排序 跟进中→已签约→已流失
- 移动端: 列表自动排序，已流失在最底部

Co-Authored-By: Claude <noreply@anthropic.com>

backend/app/api/mini_business.py

@@ -104,6 +104,9 @@ async def update_mini_business(
         update_data.pop("manager_id", None)
     for k, v in update_data.items():
         setattr(m, k, v)
+    # Auto-clear expected revenue date when status becomes 已流失
+    if m.status == "已流失" and m.expected_revenue_date:
+        m.expected_revenue_date = ""
     new_snapshot = {"customer_id": str(m.customer_id), "product_type": m.product_type, "amount": m.amount, "follow_up_detail": m.follow_up_detail, "status": m.status, "expected_revenue_date": m.expected_revenue_date}
     changes = compute_diff(old_snapshot, new_snapshot)
     if changes:

frontend/src/views/desktop/MiniBusiness.vue

@@ -39,7 +39,7 @@ const logSaving = ref(false)
 
 // ── Filters ──
 const filterManager = ref('')
-const filterStatus = ref('')
+const filterStatus = ref('跟进中')
 
 const managerOptions = computed(() => {
   const seen = new Set<string>()
@@ -49,10 +49,12 @@ const managerOptions = computed(() => {
     .sort()
 })
 
+const statusOrder: Record<string, number> = { '跟进中': 0, '已签约': 1, '已流失': 2 }
 const filteredItems = computed(() => {
   let list = miniBusiness.value
   if (filterManager.value) list = list.filter((m: any) => (m.manager_name || '未知') === filterManager.value)
   if (filterStatus.value) list = list.filter((m: any) => m.status === filterStatus.value)
+  list.sort((a: any, b: any) => (statusOrder[a.status] ?? 9) - (statusOrder[b.status] ?? 9))
   return list
 })
 

frontend/src/views/mobile/MiniBizList.vue

@@ -7,13 +7,17 @@ import { miniBusinessApi } from '@/api/miniBusiness'
 const router = useRouter()
 const loading = ref(false)
 const items = ref<any[]>([])
+const statusOrder: Record<string, number> = { '跟进中': 0, '已签约': 1, '已流失': 2 }
 
 onMounted(loadItems)
 
 async function loadItems() {
   loading.value = true
-  try { const res = await miniBusinessApi.list(); items.value = Array.isArray(res.data) ? res.data : (res.data.items || []) }
-  catch (_) {}
+  try {
+    const res = await miniBusinessApi.list()
+    const raw = Array.isArray(res.data) ? res.data : (res.data.items || [])
+    items.value = raw.sort((a: any, b: any) => (statusOrder[a.status] ?? 9) - (statusOrder[b.status] ?? 9))
+  } catch (_) {}
   finally { loading.value = false }
 }