Add Unpack tool for DACPAC files (command line only)

src/DacFXTool/Program.cs

@@ -30,7 +30,7 @@
                         && int.TryParse(args[1], out int dbTypeInt)
                         && bool.TryParse(args[0], out bool mergeDacpacs))
                     {
                         SchemaInfo[] schemas = null;
                         if (args.Length == 4)
                         {
                             schemas = args[3].Split(',').Select(s => new SchemaInfo { Name = s }).ToArray();
@@ -149,6 +149,27 @@
 
                         return 0;
                     }
+
+                    // unpack "dacpac path" "output path"
+                    if (args.Length == 3
+                        && args[0] == "unpack")
+                    {
+                        if (!new FileInfo(args[1]).Exists)
+                        {
+                            await Console.Out.WriteLineAsync("Error:");
+                            await Console.Out.WriteLineAsync($"DACPAC file '{args[1]}' not found");
+                            return 1;
+                        }
+
+                        var unpacker = new DacPackageUnpacker();
+
+                        unpacker.Unpack(args[1], args[2]);
+
+                        await Console.Out.WriteLineAsync("Result:");
+                        await Console.Out.WriteLineAsync("OK");
+
+                        return 0;
+                    }
                 }
                 else
                 {

src/DacFXToolLib/DacPackageUnpacker.cs

@@ -0,0 +1,19 @@
+using Microsoft.SqlServer.Dac;
+using System.IO;
+
+namespace DacFXToolLib
+{
+    public class DacPackageUnpacker
+    {
+        public void Unpack(string dacpacPath, string outputPath)
+        {
+            // Ensure output directory exists
+            Directory.CreateDirectory(outputPath);
+
+            using (var package = DacPackage.Load(dacpacPath))
+            {
+                DacServices.Unpack(package, outputPath);
+            }
+        }
+    }
+}