Restructure solution layout by module

src/Notify/__Libraries/StellaOps.Notify.Models/Iso8601DurationConverter.cs

@@ -0,0 +1,28 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using System.Xml;
+
+namespace StellaOps.Notify.Models;
+
+internal sealed class Iso8601DurationConverter : JsonConverter<TimeSpan>
+{
+    public override TimeSpan Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+    {
+        if (reader.TokenType is JsonTokenType.String)
+        {
+            var value = reader.GetString();
+            if (!string.IsNullOrWhiteSpace(value))
+            {
+                return XmlConvert.ToTimeSpan(value);
+            }
+        }
+
+        throw new JsonException("Expected ISO 8601 duration string.");
+    }
+
+    public override void Write(Utf8JsonWriter writer, TimeSpan value, JsonSerializerOptions options)
+    {
+        var normalized = XmlConvert.ToString(value);
+        writer.WriteStringValue(normalized);
+    }
+}