feat: 添加PLC配置并优化后台服务

refactor(PLCTool): 重构PLC工具类，优化连接处理和错误日志
fix: 修正数据库连接字符串和开发环境配置
feat(DoanBackgroundService): 添加新的后台服务实现，改进库存监控逻辑

DOAN.Admin.WebApi/appsettings.Development.json

@@ -10,7 +10,7 @@
   "dbConfigs": [
     {
 
-      "Conn": "Data Source=192.168.0.58;User ID=root;Password=123456;Initial Catalog=pbl_huaxiang;Port=3306",
+      "Conn": "Data Source=139.224.232.211;User ID=root;Password=doantech123;Initial Catalog=pbl_huaxiang;Port=3308",
       //"Conn": "Data Source=10.72.80.161;User ID=root;Password=doantech123;Initial Catalog=pbl_huaxiang_v2;Port=3306",
       "DbType": 0, //数据库类型 MySql = 0, SqlServer = 1, Oracle = 3，PgSql = 4
       "ConfigId": "0", //多租户唯一标识

DOAN.Admin.WebApi/appsettings.json

@@ -1 +1,5 @@
-{}
+{
+  "PLCConfig": {
+    "Address": "10.72.82.242"
+  }
+}