Add designer file menu and package metadata

LehrerApp.Templating/TemplatePackage.cs

@@ -10,6 +10,13 @@ public static class TemplatePackage
     public static void Create(string outputPath, TemplateManifest manifest, string layoutSource,
         IReadOnlyDictionary<string, byte[]> assets)
     {
+        if (!TemplateLoader.IsSafeRelativePath(manifest.MetadataFile))
+            throw new InvalidDataException("metadataFile enthält einen unsicheren Pfad.");
+        if (TemplateLoader.Normalize(manifest.MetadataFile).Equals(
+                TemplateLoader.Normalize(manifest.LayoutFile), StringComparison.OrdinalIgnoreCase))
+            throw new InvalidDataException("metadataFile und layoutFile dürfen nicht identisch sein.");
+        var reservedPaths = new HashSet<string>(StringComparer.OrdinalIgnoreCase)
+        { "manifest.json", TemplateLoader.Normalize(manifest.LayoutFile), TemplateLoader.Normalize(manifest.MetadataFile) };
         if (!string.Equals(Path.GetExtension(outputPath), Extension, StringComparison.OrdinalIgnoreCase))
             outputPath += Extension;
         var directory = Path.GetDirectoryName(outputPath);
@@ -21,10 +28,13 @@ public static class TemplatePackage
             {
                 WriteText(archive, "manifest.json", JsonSerializer.Serialize(manifest, TemplateLoader.JsonOptions));
                 WriteText(archive, manifest.LayoutFile, layoutSource);
+                WriteText(archive, manifest.MetadataFile, TemplateMetadataText.Serialize(manifest.Metadata));
                 foreach (var asset in assets)
                 {
                     if (!TemplateLoader.IsSafeRelativePath(asset.Key))
                         throw new InvalidDataException($"Unsicherer Assetpfad „{asset.Key}“.");
+                    if (reservedPaths.Contains(TemplateLoader.Normalize(asset.Key)))
+                        throw new InvalidDataException($"Assetpfad „{asset.Key}“ ist für Paketdaten reserviert.");
                     var entry = archive.CreateEntry(TemplateLoader.Normalize(asset.Key), CompressionLevel.Optimal);
                     using var stream = entry.Open(); stream.Write(asset.Value);
                 }