feat: add assessment workbench and September reconciliation

Preserve August hydrogen revision and September audit evidence; calculate interrupted vehicle history across all prior months. Record remaining carry-policy and layout-baseline discrepancies.

prototype/make_sample.py

@@ -0,0 +1,14 @@
+"""生成纯虚构、可经过真实本机 API 试算的样本。"""
+from pathlib import Path
+from openpyxl import Workbook
+out = Path(__file__).parent / '.data' / 'samples'
+out.mkdir(parents=True, exist_ok=True)
+w = Workbook(); s = w.active
+s.append(['vehicle_id','plate_number','contract_id','contract_code','project_name','customer_name','business_department_name','business_manager_name','delivery_vehicle_id','delivery_time','return_vehicle_task_id','return_time'])
+s.append(['demo-v1','DEMO-001','demo-c1','DEMO-CONTRACT-1','演示项目','演示客户','演示部门','示例甲','demo-l1','2026-08-01',None,None])
+w.save(out / 'demo-leases.xlsx')
+w = Workbook(); s = w.active
+s.append(['plate_number','date','mileage_km'])
+for d in range(1,32): s.append(['DEMO-001',f'2026-08-{d:02d}',120])
+w.save(out / 'demo-mileage.xlsx')
+print(out)