feat(ui): show ribbon command icons in menus and suggestions

The ribbon definition beside each command stays the one source of its
label and icon. One cached lookup (modules::registry::ribbon_commands)
walks the core ribbon and the expanded Draw/Modify panels; the shortcut
list, the right-click menu, the grip menu and the command-line
suggestions read it.

- Context menu: command rows carry their ribbon icon; Undo/Redo and
  Isolate use interface glyphs, Draw Order its ribbon icon; icons and
  the caret fade on disabled rows.
- Grip menu: Stretch, Move, Rotate, Scale, Mirror and Copy icons.
- Suggestions: an icon column, aligned when a command has none.
- Shortcut list: dropdown entries were read as (label, command) though
  the ribbon stores (command, label), so they never got a label or icon.

Reworked from #1449.

Co-Authored-By: MarcelP102 <30177694+MarcelP102@users.noreply.github.com>
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/ui/command_line.rs

@@ -798,7 +798,16 @@ impl CommandLine {
                 let mut col = column![].spacing(0).width(Length::Fill);
                 for (idx, cmd) in matches.iter().enumerate() {
                     let is_selected = idx == cursor;
-                    let row = button(text(cmd.clone()).size(11))
+                    // Every row keeps the icon's width so names line up.
+                    let icon: Element<'_, Message> =
+                        match crate::modules::registry::command_icon(cmd) {
+                            Some(bytes) => crate::ui::icons::semantic(bytes, 14.0),
+                            None => Space::new().width(14.0).into(),
+                        };
+                    let label = row![icon, text(cmd.clone()).size(11)]
+                        .spacing(6)
+                        .align_y(iced::Center);
+                    let row = button(label)
                         .on_press(Message::CommandSuggestionPick(cmd.clone()))
                         .width(Length::Fill)
                         .padding([2, 8])