feat(notification): distinguish read confirmation from signature

Add IsReadAndConfirm to DocumentSignedNotification and derive the action, status, and final action labels from it so read-only envelopes do not report a signature.

Pass the envelope read-and-confirm mode when finalizing so the signed email matches the receiver workflow.

EnvelopeGenerator.Application/Common/Interfaces/Services/Notification/DocumentSignedNotification.cs

@@ -21,7 +21,27 @@ public record DocumentSignedNotification : EnvelopeNotificationBase
     /// 
     /// </summary>
     public string NamePortal { get; init; } = "signFLOW Portal";
-    
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public required bool IsReadAndConfirm { private get; init; }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public string ReceiverAction => IsReadAndConfirm ? "bestätigt" : "unterschrieben";
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public string FinalStatus => IsReadAndConfirm ? "Lesebestätigung" : "Signatur";
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public string FinalAction => IsReadAndConfirm ? "Empfänger bestätigt" : "Vertragspartner unterzeichnet";
+
     /// <summary>
     /// 
     /// </summary>