Refactor project structure in solution

Replaced "EnvelopeGenerator.WebUI" with "EnvelopeGenerator.Server" and "EnvelopeGenerator.WebUI.Client" with "EnvelopeGenerator.Server.Client". Updated project entries, solution configuration platforms, and nested projects to reflect these changes.

EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Models/AnnotationDto.cs

@@ -0,0 +1,32 @@
+namespace EnvelopeGenerator.WebUI.Client.Models;
+
+/// <summary>
+/// Represents a pre-assigned signature annotation position on a specific page.
+/// <br/><br/>
+/// <b>Coordinate unit (X, Y):</b> Inches (GdPicture14 native unit),
+/// origin at the <b>top-left</b> corner of the page, both axes increase downward/rightward.
+/// <br/><br/>
+/// <b>Conversion to DevExpress:</b> Multiply by 100 (DX uses 1/100 inch).
+/// Convert: <c>xDX = xInches * 100.0</c>
+/// <br/>
+/// <b>Conversion to PDF Points:</b> Multiply by 72 (1 inch = 72 points).
+/// Convert: <c>xPt = xInches * 72.0</c>
+/// <br/>
+/// <b>Y-axis for PDF (bottom-left origin):</b> Flip required for iText7.
+/// Convert: <c>yPt = (pageHeightInches - yInches - elemHeightInches) * 72.0</c>
+/// </summary>
+[Obsolete("Use SignatureDto with SignatureService.")]
+public record AnnotationDto
+{
+    /// <summary>Unique identifier of the annotation.</summary>
+    public long Id { get; init; }
+
+    /// <summary>1-based page number within the document.</summary>
+    public int Page { get; init; }
+
+    /// <summary>Horizontal position in INCHES from the left edge of the page.</summary>
+    public double X { get; init; }
+
+    /// <summary>Vertical position in INCHES from the top edge of the page.</summary>
+    public double Y { get; init; }
+}