feat(asset): enhance return order with inspection, BPM approval, and event-driven cross-module linkage

- Add sourceType/sourceId/deliveryOrderId to return order table and DO
- Add inspectionRecordId to return order vehicle table and DO
- Add createFromDelivery/createFromReplacement methods to auto-create return orders
- Add startVehicleInspection/completeVehicleInspection for per-vehicle inspection flow
- Add submitApproval/withdrawApproval/updateApprovalStatus for BPM workflow
- Create ReturnApprovedEvent and ReturnOrderBpmListener
- Create DeliveryCompletedEvent for future vehicle status tracking
- Create VehicleStatusEventListener (TODO stubs for vehicle status updates)
- Create ReturnOrderEventListener to auto-create return order on permanent replacement approval
- Add BPM process definitions for replacement (with GM escalation) and return order approval

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

sql/2026-03-13-return-order-enhance.sql

@@ -0,0 +1,9 @@
+-- 还车单增强：添加来源类型、来源ID、关联交车单ID
+ALTER TABLE asset_return_order
+  ADD COLUMN source_type tinyint DEFAULT NULL COMMENT '来源：1=手动 2=替换车触发',
+  ADD COLUMN source_id bigint DEFAULT NULL COMMENT '来源业务ID',
+  ADD COLUMN delivery_order_id bigint DEFAULT NULL COMMENT '关联交车单ID';
+
+-- 还车车辆增强：添加验车记录关联
+ALTER TABLE asset_return_order_vehicle
+  ADD COLUMN inspection_record_id bigint DEFAULT NULL COMMENT '关联验车记录';