feat(财务统计): 新增月度财务报表功能

添加月度财务报表页面及相关工具函数和类型定义
修改统计接口参数类型以支持字符串格式的月份
调整空状态显示样式

apps/finance/src/router/routes/modules/statistics.ts

@@ -56,6 +56,15 @@ const routes: RouteRecordRaw[] = [
         path: '/statistics/course-report',
         component: () => import('#/views/statistics/course/report.vue'),
       },
+      {
+        meta: {
+          title: '月度财务报表',
+          keepAlive: true,
+        },
+        name: 'FinanceMonthReport',
+        path: '/statistics/finance-month-report',
+        component: () => import('#/views/statistics/summary-month/report.vue'),
+      },
     ],
   },
 ];