feat(purchase): 采购批次号支持，同一批提交的记录可分组查看/统计

背景: 循环提交把一批物品生成多条独立申请，无法识别'哪些是同一批采购'

后端:
- purchase_request 模型新增 batch_no 字段（同一批提交共享）
- create 接口接收 batch_no，无则自动生成 BATCH-yyyyMMdd-HHmm-随机
- 新增 GET /purchase/batch/<batch_no> 按批次查询所有记录
- 批量审批接口支持按 batch_no 一键审批整批

前端:
- 提交时生成 batch_no 共享给所有行
- 列表新增批次号列（可点击）
- 新增'整批查看'弹窗：显示同批次所有记录 + 一键批量通过本批
- 操作列新增'整批'按钮

数据库需执行: ALTER TABLE purchase_request ADD COLUMN batch_no VARCHAR(100);

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

@@ -157,6 +157,38 @@ def get_purchase_detail(purchase_id):
         return jsonify({'code': 500, 'msg': str(e)}), 500
 
 
+# --------------------------------------------------------
+# 3.5 按批次查询采购申请（同一批提交的多条记录）
+# GET /api/v1/purchase/batch/<batch_no>
+# --------------------------------------------------------
+@purchase_bp.route('/batch/<path:batch_no>', methods=['GET'])
+@jwt_required()
+def get_purchase_by_batch(batch_no):
+    """按批次号查询同一批提交的所有采购申请记录"""
+    try:
+        from app.models.purchase import PurchaseRequest
+        records = PurchaseRequest.query.filter(
+            PurchaseRequest.batch_no == batch_no
+        ).order_by(PurchaseRequest.id.asc()).all()
+
+        user_id = get_current_user_id()
+        has_perm = _user_has_purchase_perm()
+
+        items = []
+        for r in records:
+            d = r.to_dict()
+            # 非本人且无权限时，价格字段剥离
+            if d['requester_id'] != user_id and not has_perm:
+                for k in ('unit_price', 'total_price', 'tax_rate'):
+                    d.pop(k, None)
+            items.append(d)
+
+        return jsonify({'code': 200, 'msg': '获取成功', 'data': {'batch_no': batch_no, 'items': items}}), 200
+    except Exception as e:
+        traceback.print_exc()
+        return jsonify({'code': 500, 'msg': str(e)}), 500
+
+
 # --------------------------------------------------------
 # 4. 审批采购申请
 # PATCH /api/v1/purchase/<id>/approve
@@ -214,7 +246,9 @@ def batch_approve_purchase():
 
     请求体:
     {
-        "ids": [1, 2, 3],
+        "ids": [1, 2, 3],            // 按 ID 列表审批
+        或
+        "batch_no": "BATCH-xxx",     // 按批次号审批整批（同一批提交的记录）
         "action": "approve" | "reject",
         "reject_reason": "驳回原因（reject 时必填）"
     }
@@ -223,11 +257,23 @@ def batch_approve_purchase():
         user_id = get_current_user_id()
         data = request.get_json() or {}
         ids = data.get('ids', [])
+        batch_no = data.get('batch_no')
         action = data.get('action', 'approve')
         reject_reason = data.get('reject_reason')
 
+        # 若传 batch_no，则查出该批次的所有待审批记录 ID
+        if batch_no:
+            from app.models.purchase import PurchaseRequest
+            records = PurchaseRequest.query.filter(
+                PurchaseRequest.batch_no == batch_no,
+                PurchaseRequest.status == 0
+            ).all()
+            ids = [r.id for r in records]
+            if not ids:
+                return jsonify({'code': 400, 'msg': '该批次没有待审批的记录'}), 400
+
         if not ids or not isinstance(ids, list):
-            return jsonify({'code': 400, 'msg': 'ids 不能为空'}), 400
+            return jsonify({'code': 400, 'msg': 'ids 或 batch_no 不能为空'}), 400
         if action not in ('approve', 'reject'):
             return jsonify({'code': 400, 'msg': '无效的审批操作'}), 400
         if action == 'reject' and not reject_reason:

inventory-backend/app/models/purchase.py

@@ -11,6 +11,8 @@ class PurchaseRequest(db.Model):
 
     id = db.Column(db.Integer, primary_key=True)
     request_no = db.Column(db.String(100), unique=True, nullable=False, index=True)
+    # [新增] 采购批次号：同一批循环提交的多条记录共享，用于分组查看/统计
+    batch_no = db.Column(db.String(100), index=True, comment='采购批次号（同一批提交的多条记录共享）')
     # [新增] 硬关联基础物料表，打通"按单入库"链路
     base_id = db.Column(db.Integer, db.ForeignKey('material_base.id'), index=True, comment='关联基础物料ID')
     name = db.Column(db.String(255), nullable=False, comment='采购名称')
@@ -79,6 +81,7 @@ class PurchaseRequest(db.Model):
         return {
             'id': self.id,
             'request_no': self.request_no,
+            'batch_no': self.batch_no or '',
             'base_id': self.base_id,
             'name': self.name,
             'spec_model': self.spec_model or '',

inventory-backend/app/services/purchase_service.py

@@ -20,6 +20,18 @@ class PurchaseService:
             .filter(PurchaseRequest.request_no.like(f"{prefix}%")).scalar()
         return f"{prefix}{(existing_count + 1):04d}"
 
+    @staticmethod
+    def generate_batch_no():
+        """生成采购批次号: BATCH-yyyyMMdd-HHmm-当日流水(4位)
+        同一批循环提交的多条记录共享同一 batch_no"""
+        import uuid
+        beijing_tz = timezone(timedelta(hours=8))
+        now = datetime.now(beijing_tz)
+        date_str = now.strftime('%Y%m%d')
+        time_str = now.strftime('%H%M')
+        # 用时间戳 + 随机段确保唯一
+        return f"BATCH-{date_str}-{time_str}-{uuid.uuid4().hex[:4].upper()}"
+
     @staticmethod
     def auto_fill_from_material(keyword: str):
         """
@@ -67,8 +79,12 @@ class PurchaseService:
             if material:
                 base_id = material.id
 
+        # [新增] 批次号：前端同一批循环提交时传入同一 batch_no，无则自动生成
+        batch_no = data.get('batch_no') or PurchaseService.generate_batch_no()
+
         purchase = PurchaseRequest(
             request_no=request_no,
+            batch_no=batch_no,     # [新增]
             base_id=base_id,       # [新增]
             name=data['name'],
             spec_model=data.get('spec_model', ''),