feat(envelope): bypass access-code flow when UseAccessCode is disabled

- Add logic to skip access-code workflow if UseAccessCode is false
- Auto-authenticate receiver and show envelope immediately
- Preserve rejection and signed checks
- Keep existing behavior for access-code enabled envelopes

EnvelopeGenerator.Application/Common/Dto/EnvelopeDto.cs

@@ -82,7 +82,7 @@ public record EnvelopeDto
     /// <summary>
     /// 
     /// </summary>
-    public bool? UseAccessCode { get; set; }
+    public bool UseAccessCode { get; set; } = true;
 
     /// <summary>
     ///