Keyboard shortcuts + the '?' cheat sheet

Every keyboard shortcut is declared once, by its own operation; the same declaration drives both the key handler and a discoverable panel (press '?').

What it does

Press ? (Shift+/) anywhere in the grid to open a categorized list of every keyboard shortcut — grouped as Edit, Formatting, and Help — each row showing its action and its chord (e.g. "Bold — Ctrl+B"). Press Escape or click outside to close it.

Verified behavior

Matches Google Sheets: Individually, Studio's bindings already match Google Sheets: Ctrl+B bold, Ctrl+I italic, Ctrl+C/X/V copy/cut/paste, Ctrl+Z undo, Ctrl+Y (or Ctrl+Shift+Z) redo, Ctrl+D/R fill down/right, and Ctrl+Shift+7 all-borders are the same chords Sheets uses (each verified in its own feature manifest — format-bold.mdx, clipboard.mdx, undo.mdx, fill.mdx, format-borders.mdx — this manifest doesn't re-assert them, only that they're all reachable from one categorized list). The cheat-sheet TRIGGER itself is a deliberate divergence: Google Sheets opens its shortcut reference on Ctrl+/ (Cmd+/ on Mac). Studio binds a bare '?' (Shift+/) instead, following the newer cross-app convention (Gmail, Slack, GitHub, Trello, Notion) — chosen so it doesn't compete with Ctrl+/, which several browsers/extensions already reserve. Excel has no single-key shortcut-list binding to match either way (its shortcuts live in a Help-pane search), so there's no Excel parity claim to make here.

Shift+/ opens a categorized panel listing the registry's shortcuts

Given

When I click A1, then press Shift+?

Then

[data-testid="shortcuts-panel"] is visible containing "Bold"

Escape closes the panel