refactor(configmanager): migrate to per-file pipeline system

Align ConfigManager with DataSync's per-file pipeline format (pipeline.*.json)
by reusing EtlPipelineConfig types directly, eliminating duplicate models and
simplifying the codebase. Removes ~3200 lines of obsolete code.

NEW/tests/JdeScoping.ConfigManager.Tests/ViewModels/RegexTransformerViewModelTests.cs

@@ -1,26 +1,42 @@
-using JdeScoping.ConfigManager.Models;
 using JdeScoping.ConfigManager.ViewModels.PipelineSteps;
+using JdeScoping.DataSync.Configuration;
+using System.Text.Json;
 
 namespace JdeScoping.ConfigManager.Tests.ViewModels;
 
 public class RegexTransformerViewModelTests
 {
+    private static readonly JsonSerializerOptions JsonOptions = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase
+    };
+
+    private static TransformElement CreateElement(object config)
+    {
+        var json = JsonSerializer.Serialize(config, JsonOptions);
+        using var doc = JsonDocument.Parse(json);
+        return new TransformElement
+        {
+            TransformType = "Regex",
+            Config = doc.RootElement.Clone()
+        };
+    }
+
     [Fact]
-    public void Constructor_FromModel_LoadsAllProperties()
+    public void Constructor_FromElement_LoadsAllProperties()
     {
         // Arrange
-        var model = new TransformerModel
+        var element = CreateElement(new
         {
-            Type = "Regex",
-            ColumnName = "BatchID",
-            Pattern = "^IIS_",
-            Replacement = "",
-            IgnoreCase = true,
-            NonMatchBehavior = NonMatchBehavior.ReturnEmpty
-        };
+            columnName = "BatchID",
+            pattern = "^IIS_",
+            replacement = "",
+            ignoreCase = true,
+            nonMatchBehavior = "ReturnEmpty"
+        });
 
         // Act
-        var vm = new RegexTransformerViewModel(model, () => { });
+        var vm = new RegexTransformerViewModel(element, () => { });
 
         // Assert
         Assert.Equal("BatchID", vm.ColumnName);
@@ -32,19 +48,17 @@ public class RegexTransformerViewModelTests
     }
 
     [Fact]
-    public void Constructor_FromModel_MatchExtractMode_WhenReplacementNull()
+    public void Constructor_FromElement_MatchExtractMode_WhenReplacementNull()
     {
         // Arrange
-        var model = new TransformerModel
+        var element = CreateElement(new
         {
-            Type = "Regex",
-            ColumnName = "Code",
-            Pattern = @"(\d+)",
-            Replacement = null
-        };
+            columnName = "Code",
+            pattern = @"(\d+)"
+        });
 
         // Act
-        var vm = new RegexTransformerViewModel(model, () => { });
+        var vm = new RegexTransformerViewModel(element, () => { });
 
         // Assert
         Assert.False(vm.IsFindReplaceMode);
@@ -66,15 +80,18 @@ public class RegexTransformerViewModelTests
         };
 
         // Act
-        var model = vm.ToModel();
+        var element = vm.ToModel();
 
         // Assert
-        Assert.Equal("Regex", model.Type);
-        Assert.Equal("BatchID", model.ColumnName);
-        Assert.Equal("^IIS_", model.Pattern);
-        Assert.Equal("", model.Replacement);
-        Assert.True(model.IgnoreCase);
-        Assert.Equal(NonMatchBehavior.KeepOriginal, model.NonMatchBehavior);
+        Assert.Equal("Regex", element.TransformType);
+        Assert.True(element.Config.HasValue);
+
+        // Parse the config to verify
+        var config = element.Config!.Value;
+        Assert.Equal("BatchID", config.GetProperty("columnName").GetString());
+        Assert.Equal("^IIS_", config.GetProperty("pattern").GetString());
+        Assert.Equal("", config.GetProperty("replacement").GetString());
+        Assert.True(config.GetProperty("ignoreCase").GetBoolean());
     }
 
     [Fact]
@@ -89,10 +106,15 @@ public class RegexTransformerViewModelTests
         };
 
         // Act
-        var model = vm.ToModel();
+        var element = vm.ToModel();
 
         // Assert
-        Assert.Null(model.Replacement); // null indicates Match & Extract mode
+        Assert.True(element.Config.HasValue);
+        var config = element.Config!.Value;
+
+        // replacement should be null in Match & Extract mode
+        Assert.True(config.TryGetProperty("replacement", out var replacement));
+        Assert.Equal(JsonValueKind.Null, replacement.ValueKind);
     }
 
     [Fact]