fix: 彻底解耦出库/借库权限联动 + 路由去硬编码roles + 补API权限保护

根因: 借库选单页面14处硬编码outbound_selection:operation, 导致两模块权限联动

修复:
- borrow/apply: 14处outbound_selection:operation→op_borrow_apply:operation
- stock.py: 拆分_do_get_stock_list裸逻辑, 出库/借库各绑独立权限码
- transactions: 新增/borrow/stock-list端点(@permission(op_borrow_apply))
- transaction.ts: 新增getBorrowStockList前端API函数
- outbound.py: 出库审批4端点改用独立outbound_approval权限码
- transactions.py: 借库审批3端点补@permission(op_borrow_approval)
- purchase.py: 采购管理7端点补@permission(inbound_buy)
- audit.py: 审计日志补@permission(system_audit)
- router: 清除全部6处硬编码roles, 交由动态权限树控制

inventory-backend/app/api/v1/transactions.py

@@ -155,6 +155,7 @@ def get_records():
 # --- 提交借库申请 ---
 @trans_bp.route('/borrow/request', methods=['POST'])
 @jwt_required()
+@permission_required('op_borrow_approval')
 def submit_borrow_request():
     """
     提交借库申请（仅存储意向，不扣库存）
@@ -216,6 +217,7 @@ def submit_borrow_request():
 # --- 审批借库申请 ---
 @trans_bp.route('/borrow/request/<int:request_id>/approve', methods=['PATCH'])
 @jwt_required()
+@permission_required('op_borrow_approval')
 def approve_borrow_request(request_id):
     """
     审批借库申请
@@ -257,6 +259,7 @@ def approve_borrow_request(request_id):
 # --- 获取借库审批单列表 ---
 @trans_bp.route('/borrow/request', methods=['GET'])
 @jwt_required()
+@permission_required('op_borrow_approval')
 def get_borrow_request_list():
     """
     获取借库审批单列表
@@ -282,6 +285,16 @@ def get_borrow_request_list():
         return jsonify({'code': 500, 'msg': str(e)}), 500
 
 
+# --- 借库选单：库存查询（独立权限）---
+@trans_bp.route('/borrow/stock-list', methods=['GET'])
+@jwt_required()
+@permission_required('op_borrow_apply')
+def get_borrow_stock_list():
+    """借库选单专用库存列表，与出库选单共享底层逻辑"""
+    from app.api.v1.inbound.stock import _do_get_stock_list
+    return _do_get_stock_list()
+
+
 # --- 执行借库扣减（审批通过后调用）---
 @trans_bp.route('/borrow/dispatch', methods=['POST'])
 @jwt_required()