feat: add CincinnatiPreambleWriter for main program and variable declaration

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

OpenNest.Tests/Cincinnati/CincinnatiPreambleWriterTests.cs

@@ -0,0 +1,97 @@
+using System.IO;
+using System.Text;
+using OpenNest.Posts.Cincinnati;
+
+namespace OpenNest.Tests.Cincinnati;
+
+public class CincinnatiPreambleWriterTests
+{
+    [Fact]
+    public void WriteMainProgram_EmitsHeader()
+    {
+        var config = new CincinnatiPostConfig
+        {
+            ConfigurationName = "CL940",
+            PostedUnits = Units.Inches,
+            DefaultLibraryFile = "MS135N2PANEL.lib"
+        };
+        var sb = new StringBuilder();
+        using var sw = new StringWriter(sb);
+        var writer = new CincinnatiPreambleWriter(config);
+
+        writer.WriteMainProgram(sw, "TestNest", "Mild Steel, 10GA", 2);
+
+        var output = sb.ToString();
+        Assert.Contains("( NEST TestNest )", output);
+        Assert.Contains("( CONFIGURATION - CL940 )", output);
+        Assert.Contains("G20", output);
+        Assert.Contains("M42", output);
+        Assert.Contains("G89 P MS135N2PANEL.lib", output);
+        Assert.Contains("M98 P100 (Variable Declaration)", output);
+        Assert.Contains("GOTO1 (GOTO SHEET NUMBER)", output);
+        Assert.Contains("N1M98 P101 (SHEET 1)", output);
+        Assert.Contains("N2M98 P102 (SHEET 2)", output);
+        Assert.Contains("M30 (END OF MAIN)", output);
+    }
+
+    [Fact]
+    public void WriteMainProgram_EmitsG21ForMetric()
+    {
+        var config = new CincinnatiPostConfig { PostedUnits = Units.Millimeters };
+        var sb = new StringBuilder();
+        using var sw = new StringWriter(sb);
+        var writer = new CincinnatiPreambleWriter(config);
+
+        writer.WriteMainProgram(sw, "Test", "", 1);
+
+        Assert.Contains("G21", sb.ToString());
+    }
+
+    [Fact]
+    public void WriteMainProgram_EmitsG61_WhenExactStop()
+    {
+        var config = new CincinnatiPostConfig { UseExactStopMode = true };
+        var sb = new StringBuilder();
+        using var sw = new StringWriter(sb);
+        var writer = new CincinnatiPreambleWriter(config);
+
+        writer.WriteMainProgram(sw, "Test", "", 1);
+
+        Assert.Contains("G61", sb.ToString());
+    }
+
+    [Fact]
+    public void WriteMainProgram_OmitsG61_WhenNotExactStop()
+    {
+        var config = new CincinnatiPostConfig { UseExactStopMode = false };
+        var sb = new StringBuilder();
+        using var sw = new StringWriter(sb);
+        var writer = new CincinnatiPreambleWriter(config);
+
+        writer.WriteMainProgram(sw, "Test", "", 1);
+
+        Assert.DoesNotContain("G61", sb.ToString());
+    }
+
+    [Fact]
+    public void WriteVariableDeclaration_EmitsSubprogram()
+    {
+        var config = new CincinnatiPostConfig();
+        var vars = new ProgramVariableManager();
+        vars.GetOrCreate("LeadInFeedrate", 126, "[#148*0.5]");
+        vars.GetOrCreate("CircleFeedrate", 128, ".8");
+
+        var sb = new StringBuilder();
+        using var sw = new StringWriter(sb);
+        var writer = new CincinnatiPreambleWriter(config);
+
+        writer.WriteVariableDeclaration(sw, vars);
+
+        var output = sb.ToString();
+        Assert.Contains(":100", output);
+        Assert.Contains("(Variable Declaration Start)", output);
+        Assert.Contains("#126=", output);
+        Assert.Contains("#128=", output);
+        Assert.Contains("M99 (Variable Declaration End)", output);
+    }
+}