feat(scheduling): history view, execute/cancel lifecycle, CSV export, 7d trend

- Add 调度记录 modal: lists notifications by status, supports 标记已执行 (with
  after-mileage + notes) and 取消 for open records
- Add CSV export of filtered suggestions (UTF-8 BOM for Excel); top candidate
  per row picked by same-region > can-qualify preference
- Compute customer 7-day average alongside 30-day baseline in a single query;
  show trend indicator (up/down/flat) next to 客户日均 in list and detail card

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/shared/scheduling/types.ts

@@ -17,6 +17,7 @@ export interface SchedulingVehicleInfo {
   department: string | null;
   manager: string | null;
   customerAvgDaily: number;
+  customerAvgDaily7d: number;
   predictedYearEnd: number;
   daysLeft: number;
 }