R5.6: ElyShow right-click menus, PowerPoint-style; Impress table borders drag; R3 PASS

The canvas offers Ely's menu by target: slide (layouts, comment), text
(bullets, numbering, comment), shape or text box, picture (replace,
crop), table (insert, delete, merge), each item gated by the kernel's
state for its own command. Impress's table borders read as text and
drag through R5.3's path; patch 0047 reports every edge's bounds and
makes the left edge drag. A line past its bound never moves against
the drag, so a still press sends nothing.

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

apps/ely-table/src/menu.rs

@@ -211,9 +211,9 @@ impl Book {
         };
         let kind = match offered.target {
             Target::Cell => Kind::Cell,
-            Target::Object => Kind::Object,
+            Target::Object | Target::Picture => Kind::Object,
             Target::Text => Kind::Text,
-            Target::Table | Target::Frame => {
+            Target::Table | Target::Frame | Target::Slide => {
                 let error = format!("a {:?} menu in a spreadsheet", offered.target);
                 return self.toast(Book::text(cx, "office.error.engine", &[("error", &error)]), Severity::Danger, cx);
             }