✨ feat(*): 添加扫码枪启动探活、全局退出助手及 README

- 添加扫码枪串口启动探活，检测端口占用并更新 UI 状态
- 新增 ShutdownHelper 安全停止 Host 扩展方法
- 新增 README.md 项目说明文档
- 更新 WorkflowHostedService 启动探活逻辑
- 补充 ShutdownHelper 与 WorkflowHostedService 单元测试
- 优化 DashboardPage 与 SystemSettingsPage 界面布局
- 调整 ModbusTcpPlcService 监控镜像读取逻辑

src/AxiOmron.PcbCheck/appConfig.json

@@ -5,35 +5,19 @@
     "UnitId": 1,
     "PollIntervalMs": 200,
     "ConnectTimeoutMs": 3000,
-    "HeartbeatIntervalMs": 500,
     "ReleasePulseMs": 500,
     "ReleaseAckTimeoutMs": 2000,
     "Inputs": {
-      "PlcReady": 10001,
-      "PcbArrived": 10002,
-      "PlcReset": 10003,
-      "PlcAckRelease": 10004,
-      "AutoMode": 10005,
-      "StationEnable": 10006
+      "PcbArrived": 0,
+      "PlcReset": 1,
+      "PlcAckRelease": 2
     },
     "Outputs": {
-      "PcOnline": 51,
-      "PcBusy": 52,
-      "ScanOk": 53,
-      "ScanNg": 54,
-      "FileFound": 55,
-      "FileNotFound": 56,
-      "AlarmRaised": 57,
-      "ReleasePermit": 58,
-      "ProcessDone": 59,
-      "SystemFault": 60
+      "PcBusy": 51,
+      "ReleasePermit": 52
     },
     "Registers": {
-      "ResultCode": 40001,
-      "ScanTryCount": 40002,
-      "SftpTryCount": 40003,
-      "AlarmCode": 40004,
-      "FlowStateCode": 40005
+      "ResultCode": 0
     }
   },
   "Scanner": {
@@ -76,9 +60,6 @@
     }
   },
   "Workflow": {
-    "RequirePlcReady": true,
-    "RequireAutoMode": true,
-    "RequireStationEnable": true,
     "RequireManualResetAfterFault": true,
     "MaxUiLogEntries": 200,
     "MaxBoardRecords": 100