✨ feat(*): 重构PCB放行流程并接入双扫码校验

- 将流程改为 OMRON FINS + TCP 双扫码 + SFTP 文件校验
- 新增文件校验与扫码结果汇总实现，补充对应单测
- 同步更新流程设计文档、配置和系统设置页面文案

tests/AxiOmron.PcbCheck.Tests/DualScannerResultMergerTests.cs

@@ -0,0 +1,64 @@
+using AxiOmron.PcbCheck.Models;
+using AxiOmron.PcbCheck.Services.Implementations;
+using Xunit;
+
+namespace AxiOmron.PcbCheck.Tests;
+
+/// <summary>
+/// 验证双扫码枪结果汇总规则。
+/// </summary>
+public sealed class DualScannerResultMergerTests
+{
+    /// <summary>
+    /// 任一扫码枪成功时，应使用成功条码继续后续 SFTP 流程。
+    /// </summary>
+    [Fact]
+    public void Merge_ShouldUseSecondBarcode_WhenOnlySecondScannerSucceeds()
+    {
+        var first = new ScanOperationResult
+        {
+            IsSuccess = false,
+            DeviceConnected = true,
+            ErrorMessage = "扫码枪1超时"
+        };
+        var second = new ScanOperationResult
+        {
+            IsSuccess = true,
+            DeviceConnected = true,
+            Barcode = "PCB-SECOND"
+        };
+
+        ScanOperationResult result = DualScannerResultMerger.Merge(first, second);
+
+        Assert.True(result.IsSuccess);
+        Assert.Equal("PCB-SECOND", result.Barcode);
+        Assert.Contains("扫码枪2", result.RawMessage);
+    }
+
+    /// <summary>
+    /// 两把扫码枪都成功但内容不一致时，应优先使用扫码枪1条码并保留不一致说明。
+    /// </summary>
+    [Fact]
+    public void Merge_ShouldPreferFirstBarcode_WhenBothScannersReturnDifferentBarcodes()
+    {
+        var first = new ScanOperationResult
+        {
+            IsSuccess = true,
+            DeviceConnected = true,
+            Barcode = "PCB-FIRST"
+        };
+        var second = new ScanOperationResult
+        {
+            IsSuccess = true,
+            DeviceConnected = true,
+            Barcode = "PCB-SECOND"
+        };
+
+        ScanOperationResult result = DualScannerResultMerger.Merge(first, second);
+
+        Assert.True(result.IsSuccess);
+        Assert.Equal("PCB-FIRST", result.Barcode);
+        Assert.Contains("不一致", result.ErrorMessage);
+        Assert.Contains("PCB-SECOND", result.RawMessage);
+    }
+}