feat(ui): classic pull-down menu bar and ribbon toggle

MENUBAR 1 shows File, Edit, View, Insert, Format, Tools, Draw,
Dimension, Modify, Parametric and Help menus above the ribbon; every
entry runs an existing command, and a test keeps each entry pointing at
a registered command. RIBBONCLOSE hides the ribbon and RIBBON brings it
back, so the menus can replace it. Both choices persist.

Also translates the "File" label, which every locale had left in
English.

Refs #1450

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/ui/mod.rs

@@ -8,6 +8,7 @@ pub mod dock;
 pub mod icons;
 pub mod modal;
 pub mod node_graph;
+pub mod menu_bar;
 pub mod overlay;
 pub mod popup;
 pub mod properties;