业务更名为撞车并切换crash路由

用户可见文案与页面/API路径改为撞车与crash，保留mohong表与权限码兼容；移动端入口去掉租/撞图标。

frontend/src/features/mohong/views/MohongListView.vue

@@ -180,7 +180,7 @@ function syncQuery() {
   const query: Record<string, string> = {}
   if (keyword.value.trim()) query.keyword = keyword.value.trim()
   if (activeCategoryId.value) query.category_id = String(activeCategoryId.value)
-  router.replace({ path: '/mohong', query })
+  router.replace({ path: '/crash', query })
 }
 
 const activeCategoryName = () => {
@@ -196,7 +196,7 @@ async function handleSupportClick() {
   if (supportLoading.value) return
   supportLoading.value = true
   try {
-    const chat = await ensureSupportChat('mohong')
+    const chat = await ensureSupportChat('crash')
     router.push(`/messages/${chat.id}`)
   } catch {
     ElMessage.error('联系客服失败，请稍后重试')
@@ -210,7 +210,7 @@ async function handleSupportClick() {
   <section class="mohong-pc-page">
     <header class="toolbar">
       <div class="title-block">
-        <h1>摸大红</h1>
+        <h1>撞车</h1>
         <span class="count">{{ total }} 件</span>
         <span class="tip">{{ activeCategoryName() }} · 支付后扫码联系客服</span>
       </div>
@@ -228,7 +228,7 @@ async function handleSupportClick() {
           <el-icon><ShoppingCart /></el-icon>
           <span>购物车{{ cartCount > 0 ? `(${cartCount})` : '' }}</span>
         </button>
-        <button type="button" class="toolbar-btn outline" @click="router.push('/mohong/orders')">
+        <button type="button" class="toolbar-btn outline" @click="router.push('/crash/orders')">
           <el-icon><Tickets /></el-icon>
           <span>我的订单</span>
         </button>