feat: add position and size properties to ElementAnnotation entity

- Added `X`, `Y`, `Width`, and `Height` properties with `float` database mapping.
- Retains existing fields and database annotations.
- Prepares the entity for spatial layout handling in documents.

EnvelopeGenerator.Domain/Entities/ElementAnnotation.cs

@@ -36,6 +36,34 @@ public class ElementAnnotation
     [Column("TYPE", TypeName = "nvarchar(50)")]
     public string Type { get; set; }
 
+    [Column("POSITION_X", TypeName = "float")]
+    public double
+#if NET
+        ?
+#endif
+        X { get; set; }
+
+    [Column("POSITION_Y", TypeName = "float")]
+    public double
+#if NET
+        ?
+#endif
+        Y { get; set; }
+
+    [Column("WIDTH", TypeName = "float")]
+    public double
+#if NET
+        ?
+#endif
+        Width { get; set; }
+
+    [Column("HEIGHT", TypeName = "float")]
+    public double
+#if NET
+        ?
+#endif
+        Height { get; set; }
+
     [Required]
     [Column("ADDED_WHEN", TypeName = "datetime")]
     public DateTime AddedWhen { get; set; }