refactor(pep-lib): replace DotNetZip with System.IO.Compression and refactor readers

- Remove DotNetZip package from PepLib.Core.csproj
- Update DrawingReader, NestReader, and ZipHelper to use System.IO.Compression.ZipArchive
- Simplify stream handling and improve resource disposal
- Keep behavior consistent for loop/plate detection and extraction

PepLib.Core/IO/DrawingReader.cs

@@ -1,7 +1,7 @@
-using Ionic.Zip;
 using System;
 using System.Diagnostics;
 using System.IO;
+using System.IO.Compression;
 using System.Text.RegularExpressions;
 
 namespace PepLib.IO
@@ -22,48 +22,32 @@ namespace PepLib.IO
 
         public void Read(Stream stream)
         {
-            var zipStream = new ZipInputStream(stream);
-
-            ZipEntry theEntry;
-
-            while ((theEntry = zipStream.GetNextEntry()) != null)
+            using (var zip = new ZipArchive(stream, ZipArchiveMode.Read, leaveOpen: true))
             {
-                var size = 2048;
-                var data = new byte[size];
-                var memstream = new MemoryStream();
-
-                while (true)
+                foreach (var entry in zip.Entries)
                 {
-                    size = zipStream.Read(data, 0, data.Length);
+                    using var entryStream = entry.Open();
+                    var memstream = new MemoryStream();
+                    entryStream.CopyTo(memstream);
+                    memstream.Seek(0, SeekOrigin.Begin);
 
-                    if (size > 0)
+                    var extension = Path.GetExtension(entry.FullName);
+
+                    switch (extension)
                     {
-                        memstream.Write(data, 0, size);
-                        memstream.Flush();
+                        case ".dir":
+                            LoadInfo(memstream);
+                            memstream.Close();
+                            continue;
                     }
-                    else break;
+
+                    if (Regex.IsMatch(extension, "loop-\\d\\d\\d"))
+                        Drawing.Loops.Add(ReadLoop(entry.FullName, memstream));
+
+                    memstream.Close();
                 }
-
-                memstream.Seek(0, SeekOrigin.Begin);
-
-                var extension = Path.GetExtension(theEntry.FileName);
-
-                switch (extension)
-                {
-                    case ".dir":
-                        LoadInfo(memstream);
-                        memstream.Close();
-                        continue;
-                }
-
-                if (Regex.IsMatch(extension, "loop-\\d\\d\\d"))
-                    Drawing.Loops.Add(ReadLoop(theEntry.FileName, memstream));
-
-                memstream.Close();
             }
 
-            zipStream.Close();
-
             Drawing.ResolveLoops();
         }
 
@@ -111,3 +95,4 @@ namespace PepLib.IO
         }
     }
 }
+