feat(xref): wider panel default, Attach DWG/Image/PDF menu, status icons

External References dock default 360 to 460 for the column-rich table. Attach split button reads Attach DWG with Attach Image and Attach PDF options, all menu rows full width. List view shows one distinct glyph and theme color per reference status.

src/locale_catalog.rs

@@ -3158,6 +3158,8 @@ pub(super) fn message_attribute(source: &str) -> Option<(&'static str, &'static
         "XREF: cannot bind nested reference '{}'. Bind it in its host drawing." => Some(("insert", "xref-cannot-bind-nested-reference")),
         "Unreferenced" => Some(("insert", "unreferenced")),
         "File References" => Some(("insert", "xref-file-references")),
+        "Attach DWG" => Some(("insert", "xref-attach-dwg")),
+        "Attach Image" => Some(("insert", "xref-attach-image")),
         "Change Path" => Some(("insert", "xref-change-path")),
         "Make Absolute" => Some(("insert", "xref-make-absolute")),
         "Make Relative" => Some(("insert", "xref-make-relative")),