R5.5: ElyTable right-click menus, Excel-style; three rounds used, last fixes tested

Grid and header menus share ely_office::menu with ElyDoc. Each item's
availability is the kernel's state for the exact command it runs
(patch 0045). Patch 0046 lets a header select its row or column while
a shape is selected or its text is edited: the view shell ends the
drawing edit, keeps the typed text, leaves drawing mode, then marks.
Ely no longer sends Esc first.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

apps/ely-table/src/main.rs

@@ -11,6 +11,7 @@ mod figures;
 mod format;
 mod formulas;
 mod grid;
+mod menu;
 mod output;
 mod page;
 mod protect;