Background dialog: adjust an image's offset and scale; visual style names

- The Image tab gains an Adjust card: X/Y offset in pixels (-2000..2000)
  and X/Y scale (-10..10, tenth steps, a negative scale mirrors, zero keeps
  the image's scale) with spinners and Reset, inactive while the image is
  stretched; Keep aspect ratio is a switch and makes both scales follow.
- The preview shows the image at its offset and scale, tiled when tiled,
  and a stretched image kept to its aspect ratio covers the view.
- Automation: step=<field>,+1|-1 and reset; offset/scale take any numbers.
- Shaded with edges, Shades of Gray and Sketchy have catalog entries in
  every language.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/locale_catalog.rs

@@ -2994,6 +2994,8 @@ pub(super) fn message_attribute(source: &str) -> Option<(&'static str, &'static
         "Shade plot" => Some(("common", "shade-plot")),
         "Shaded" => Some(("view", "shaded")),
         "Shaded viewport options" => Some(("plot", "shaded-viewport-options")),
+        "Shaded with edges" => Some(("common", "shaded-with-edges")),
+        "Shades of Gray" => Some(("common", "shades-of-gray")),
         "Shadow flags" => Some(("common", "shadow-flags")),
         "Shadows" => Some(("properties", "shadows")),
         "Shape" => Some(("properties", "shape")),
@@ -3020,6 +3022,7 @@ pub(super) fn message_attribute(source: &str) -> Option<(&'static str, &'static
         "SingleLine" => Some(("properties", "singleline")),
         "Size" => Some(("common", "size")),
         "Sketch" => Some(("draw", "sketch")),
+        "Sketchy" => Some(("common", "sketchy")),
         "Snap override: {label} (next pick only)." => Some(("common", "snap-override-label-next-pick-only")),
         "Snap to\nUnderlays" => Some(("insert", "snap-to-underlays")),
         "Softness" => Some(("properties", "softness")),