docs: Add XML documentation to IZip interface (#1737)

Add comprehensive XML documentation for the IZip interface including:
- Interface-level summary describing ZIP compression/decompression functionality
- ZipFolder method overloads with parameter and return value documentation
- UnZipToFolder method overloads with parameter and return value documentation

Fixes #1517

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Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: thomhurst

src/ModularPipelines/Context/IZip.cs

@@ -4,13 +4,42 @@
 
 namespace ModularPipelines.Context;
 
+/// <summary>
+/// Provides ZIP compression and decompression functionality for folders and files.
+/// </summary>
 public interface IZip
 {
+    /// <summary>
+    /// Compresses a folder into a ZIP file using optimal compression level.
+    /// </summary>
+    /// <param name="folder">The folder to compress.</param>
+    /// <param name="outputPath">The path where the ZIP file will be created.</param>
+    /// <returns>A <see cref="File"/> representing the created ZIP file.</returns>
     public File ZipFolder(Folder folder, string outputPath) => ZipFolder(folder, outputPath, CompressionLevel.Optimal);
 
+    /// <summary>
+    /// Compresses a folder into a ZIP file with the specified compression level.
+    /// </summary>
+    /// <param name="folder">The folder to compress.</param>
+    /// <param name="outputPath">The path where the ZIP file will be created.</param>
+    /// <param name="compressionLevel">The level of compression to use.</param>
+    /// <returns>A <see cref="File"/> representing the created ZIP file.</returns>
     public File ZipFolder(Folder folder, string outputPath, CompressionLevel compressionLevel);
 
+    /// <summary>
+    /// Extracts a ZIP file to a folder, overwriting existing files by default.
+    /// </summary>
+    /// <param name="zipPath">The path to the ZIP file to extract.</param>
+    /// <param name="outputFolderPath">The path where the contents will be extracted.</param>
+    /// <returns>A <see cref="Folder"/> representing the extraction destination folder.</returns>
     public Folder UnZipToFolder(string zipPath, string outputFolderPath) => UnZipToFolder(zipPath, outputFolderPath, true);
 
+    /// <summary>
+    /// Extracts a ZIP file to a folder with control over whether to overwrite existing files.
+    /// </summary>
+    /// <param name="zipPath">The path to the ZIP file to extract.</param>
+    /// <param name="outputFolderPath">The path where the contents will be extracted.</param>
+    /// <param name="overwriteFiles">If <c>true</c>, existing files will be overwritten; otherwise, an exception is thrown for conflicts.</param>
+    /// <returns>A <see cref="Folder"/> representing the extraction destination folder.</returns>
     public Folder UnZipToFolder(string zipPath, string outputFolderPath, bool overwriteFiles);
 }