feat(web/route): 适配移动端响应式布局 + 统一站点拖拽逻辑

1. 线路规划页面(/route)移动端适配:
   - 新增 980px / 768px / 480px 三档响应式CSS
   - 侧边栏改为抽屉式叠加层，主容器垂直流式布局
   - 顶部导航、工具栏、编辑器堆叠式排列
   - SVG线路容器开启横向惯性滚动，最小宽度720px
   - 票价地图、表格、模态框均针对小屏优化
   - 按钮/输入框统一最小高度44px，满足可访问性

2. 重构站点拖拽逻辑（修复电脑端拖拽失效）:
   - 原实现：mousemove绑定单站点<g>，鼠标离开即丢失拖拽
   - 新实现：mousedown/touchstart仅记录起点，
     window级别监听 mousemove/mouseup/touchmove/touchend
   - 通过 SVG createSVGPoint + getScreenCTM().inverse()
     统一将屏幕坐标转换为SVG逻辑坐标再换算站点索引
   - 共用 swapStationByIndex() / saveDragResult() 核心函数

3. 静态资源版本号升级: style.css v16, ticket-route.js v5

web/ticket-route.html

@@ -8,7 +8,7 @@
     <title>线路规划|FSE铁路运输票务系统</title>
     <link rel="icon" type="image/png" href="/FSE-ticket.png">
     <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/css/all.min.css">
-    <link rel="stylesheet" href="/style.css?v=14">
+    <link rel="stylesheet" href="/style.css?v=16">
     <script src="https://unpkg.com/vue@3/dist/vue.global.prod.js"></script>
     <script src="/socket.io/socket.io.js"></script>
 </head>
@@ -239,8 +239,10 @@
 
                                     <!--车站节点-->
                                     <g v-for="(sCode, index) in selectedLine.stations" :key="sCode"
-                                        @mousedown="onStationDragStart(index)" @mouseup="onStationDrop"
-                                        @mousemove="onStationDragOver(index)" @click="handleStationClick(sCode)"
+                                        @mousedown="onStationDragStart(index, $event)"
+                                        @mouseup="onStationDrop"
+                                        @click="handleStationClick(sCode)"
+                                        @touchstart.passive="onStationTouchStart(index, $event)"
                                         class="station-node" :class="{
                                            'selected': isStationSelected(sCode),
                                            'fare-source': fareSelection[0] === sCode,
@@ -600,7 +602,7 @@
     </div>
     <script src="/custom-dialog.js?v=11"></script>
     <script src="/public-status.js?v=14"></script>
-    <script src="ticket-route.js?v=3"></script>
+    <script src="ticket-route.js?v=5"></script>
     <script>
         document.addEventListener('DOMContentLoaded', () => {
             const isDomain = location.hostname.includes('fse-media.group');