Add mail assistant (#84)

app/MindWork AI Studio/Settings/DataModel/Data.cs

@@ -42,4 +42,6 @@ public sealed class Data
     public DataGrammarSpelling GrammarSpelling { get; init; } = new();
     
     public DataRewriteImprove RewriteImprove { get; init; } = new();
+
+    public DataEMail EMail { get; set; } = new();
 }

app/MindWork AI Studio/Settings/DataModel/DataEMail.cs

@@ -0,0 +1,42 @@
+using AIStudio.Assistants.EMail;
+using AIStudio.Tools;
+
+namespace AIStudio.Settings.DataModel;
+
+public sealed class DataEMail
+{
+    /// <summary>
+    /// Preselect any rewrite options?
+    /// </summary>
+    public bool PreselectOptions { get; set; }
+    
+    /// <summary>
+    /// Preselect the target language?
+    /// </summary>
+    public CommonLanguages PreselectedTargetLanguage { get; set; }
+    
+    /// <summary>
+    /// Preselect any other language?
+    /// </summary>
+    public string PreselectOtherLanguage { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Preselect any writing style?
+    /// </summary>
+    public WritingStyles PreselectedWritingStyle { get; set; }
+    
+    /// <summary>
+    /// Preselect a provider?
+    /// </summary>
+    public string PreselectedProvider { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Preselect a greeting phrase?
+    /// </summary>
+    public string Greeting { get; set; } = string.Empty;
+    
+    /// <summary>
+    /// Preselect the sender name for the closing salutation?
+    /// </summary>
+    public string SenderName { get; set; } = string.Empty;
+}