Added the BeyondFacts Lab as a prototype (#1175)

app/MindWork AI Studio/Assistants/BeyondFactsLab/BeyondFactsLabJson.cs

@@ -0,0 +1,31 @@
+using System.Text.Encodings.Web;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace AIStudio.Assistants.BeyondFactsLab;
+
+/// <summary>
+/// The JSON options of the files of the BeyondFacts Lab.
+/// </summary>
+internal static class BeyondFactsLabJson
+{
+    /// <summary>
+    /// The options with which the lab writes and reads its files.
+    /// </summary>
+    /// <remarks>
+    /// The files stay readable for people who look into the data folder: indented, enums by name, and umlauts
+    /// as they are rather than as escapes. The relaxed encoder is fine here, because nothing embeds these files
+    /// into HTML. A field this version does not know makes a file unreadable rather than letting a save drop
+    /// it; such a preparation is listed as one of a newer version or as unavailable, and nothing writes it.
+    /// </remarks>
+    internal static readonly JsonSerializerOptions PERSISTENCE = new JsonSerializerOptions
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+        PropertyNameCaseInsensitive = false,
+        WriteIndented = true,
+        Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping,
+        UnmappedMemberHandling = JsonUnmappedMemberHandling.Disallow,
+        Converters = { new JsonStringEnumConverter() },
+        TypeInfoResolver = BeyondFactsLabJsonContext.Default,
+    }.AsReadOnly();
+}