fix: 修复多处边界条件问题

- rooms: parseRoomNumber 未知格式返回默认 capacity=4，防止 undefined 绕过入住容量检查
- rooms: 修复 parseInt() || undefined 导致楼层 0 被吞掉
- rooms: batchImport 中 capacity 使用 ?? 代替 ||，显式 0 不被覆盖
- occupancies: 所有 capacity 比较加 ?? 0 防守兜底，fail closed
- schedules: assertValidScheduleRange 增加 startTime > endTime 校验
- attendance: 时段重叠检查改为按 startTime 排序后再比较，消除漏检
- attendance: 移除 getScheduleOptionsForAttendance 中不可靠的 raw[index] fallback
- expenses: 个人附加费批量导入增加 assertPositiveAmount 校验
- expenses: 水电费导入增加 periodEnd >= periodStart 校验

apps/server/src/rooms/rooms.controller.ts

@@ -349,7 +349,7 @@ export class RoomsController {
       rows.push({
         roomNumber: String(row.getCell(1).value || ''),
         building: String(row.getCell(2).value || '') || undefined,
-        floor: Number(row.getCell(3).value) || undefined,
+        floor: (n => Number.isNaN(n) ? undefined : n)(Number(row.getCell(3).value)),
         capacity: Number(row.getCell(4).value) || 4,
         roomType: String(row.getCell(5).value || '').trim() || undefined,
         rentalCategory,