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

src/ui/ribbon/draw_panel.rs

@@ -126,6 +126,15 @@ const PANELS: &[Panel] = &[
     },
 ];
 
+/// Command, label and icon of every tool in the expanded Draw and Modify
+/// panels.
+pub(crate) fn tools() -> impl Iterator<Item = (&'static str, &'static str, &'static [u8])> {
+    PANELS
+        .iter()
+        .flat_map(|panel| panel.tools)
+        .map(|tool| (tool.command, tool.label, tool.icon))
+}
+
 fn panel_for_dropdown(id: &str) -> Option<Panel> {
     PANELS.iter().copied().find(|panel| {
         panel.id == id

src/ui/ribbon/mod.rs

@@ -22,6 +22,7 @@ use crate::ui::properties::{linetype_display_name, lw_options, LinetypeItem};
 
 mod widgets;
 mod draw_panel;
+pub(crate) use draw_panel::tools as panel_tools;
 mod modify_panel;
 mod color_dropdown;
 use widgets::{StyleContext, *};