TASK 61 + 62: the geometry fields share one width, and the border field names its colour

The creator (2026-10-21), on Live -> Layers -> webcam -> Properties:

  "the Y and H boxes under webcam properties should be the same width as the X and W
   boxes and those widths should be fixed to accomodate the max number of possible
   digits providing the geometry values"

  "also the border color drop drown box content should also include the name of the
   color next to the hex value as they in the drop-down list box"

TASK 61 - one fixed width for the four geometry fields.
The row is a DockPanel, and WPF sizes an element to its CONTENT unless it is told
otherwise, while the LAST child of a DockPanel fills the remaining space. So X/W (not
last) were as wide as their text and Y/H (last) stretched across the row - two widths
for the same kind of field. Now all four carry Width="44" and the rows set
LastChildFill="False" (without it the last field ignores its own Width and fills anyway).
44px is the measured width of "-1920" in the app's font at 11px (the largest geometry
value - the master frame is 1920x1080 - plus a sign) plus the field's padding and
border. Docs: https://learn.microsoft.com/en-us/dotnet/api/system.windows.controls.dockpanel.lastchildfill
The guard MEASURES the widest value with WPF's FormattedText instead of asserting a
magic number, so a font change cannot silently make the field too narrow:
https://learn.microsoft.com/en-us/dotnet/api/system.windows.media.formattedtext

TASK 62 - the border field names its colour.
SceneElement.BorderColorName carries the palette's name for the current colour
("Crimson") and is raised when the colour changes; it is EMPTY for a custom hex the
creator typed, because "no name" is the honest answer. BorderColorPalette.NameOf
changed to match (it used to fall back to the hex itself; the TASK 60 test assertion
was updated with it). The hex field keeps a fixed width (60) so the name sits right
next to the hex instead of drifting to the row's far edge - the same trap as TASK 61.

Guards: ytLive.Tests/GeometryFieldWidthTests.cs, ytLive.Tests/BorderColorNameTests.cs
Full suite: 435/435 passed, 0 warnings.

Models/SceneElement.cs

@@ -264,10 +264,16 @@ public abstract class SceneElement : INotifyPropertyChanged
             {
                 Raise(nameof(HasBorder));
                 Raise(nameof(BorderBrush));
+                Raise(nameof(BorderColorName));
             }
         }
     }
 
+    /// <summary>The palette's name for the current border colour — "Crimson" for
+    /// #e94560, and EMPTY for a custom hex the creator typed (the field shows the hex
+    /// alone then). Shown next to the hex field (TASK 62).</summary>
+    public string BorderColorName => BorderColorPalette.NameOf(BorderColor);
+
     private double _borderOpacity = 1.0;
     public double BorderOpacity
     {