feat: 采购单导入自动填充采购人/邮箱/详情链接 + 实时搜索

- PurchaseRequest.to_dict() 新增 requester_email
- 导入时自动填入: 采购人(requester_name) + 邮箱(requester_email) + 详情链接(supplier_link)
- 移除原始链接/详情链接的历史 autocomplete, 改为纯输入框+权限守卫
- 采购单导入搜索改为实时输入搜索(300ms防抖), 保留搜索按钮

inventory-backend/app/models/purchase.py

@@ -64,6 +64,16 @@ class PurchaseRequest(db.Model):
         except Exception:
             return f"用户({user_id})"
 
+    def _get_user_email(self, user_id):
+        if not user_id:
+            return ""
+        from app.models.system import SysUser
+        try:
+            user = db.session.get(SysUser, user_id)
+            return user.email or "" if user else ""
+        except Exception:
+            return ""
+
     def to_dict(self):
         return {
             'id': self.id,
@@ -82,6 +92,7 @@ class PurchaseRequest(db.Model):
             'status_text': ['待审批', '已通过', '已驳回', '已完成'][self.status] if self.status in [0, 1, 2, 3] else '未知',
             'requester_id': self.requester_id,
             'requester_name': self._get_user_name(self.requester_id),
+            'requester_email': self._get_user_email(self.requester_id),
             'approver_id': self.approver_id,
             'approver_name': self._get_user_name(self.approver_id) if self.approver_id else None,
             'approved_at': self.approved_at.strftime('%Y-%m-%d %H:%M:%S') if self.approved_at else None,