feat(ticket): 新增单程票购票与检票功能，优化日志与接口

- 前端新增单程票购票界面，支持票种切换与区间选择、价格预览
- 完善后端检票接口，添加单程票的校验与处理逻辑
- 优化售票机脚本的车票类型映射，新增单程车票支持
- 简化前端售票日志输出，移除冗余站点信息字段
- 新增服务层付费区间计算字段，优化公共接口返回数据

server/services/logic.js

@@ -231,7 +231,8 @@ const LogicService = {
           regular_path: [src],
           express_path: [src],
           regular_transfers: [],
-          express_transfers: []
+          express_transfers: [],
+          paid_segments: 0
         };
       }
 
@@ -245,6 +246,7 @@ const LogicService = {
       const totals = accumulateFareAlongPath(graph, result.path);
       if (!totals) return null;
       const transfers = computeTransfersAlongPath(graph, result.path);
+      const dstCost = result.dist.get(dst);
 
       return {
         regular: Math.round(Number(totals.regular ?? 0) || 0),
@@ -253,6 +255,7 @@ const LogicService = {
         express_path: result.path,
         regular_transfers: transfers,
         express_transfers: transfers,
+        paid_segments: dstCost ? dstCost.paidSegments : Infinity
       };
     } catch (_) { return null; }
   },