Issue: MEDIUM priority from canvas accessibility audit (2026-05-09).
The existing Quick Start help dialog in Toolbar omitted most keyboard shortcuts
from useKeyboardShortcuts.ts — users couldn't discover them visually.
Changes:
- Toolbar.tsx: enhance the help dialog (role="dialog") to include all
documented shortcuts: Esc, Enter, Shift+Enter, Cmd+], Cmd+[, Z, plus
mouse interaction tips for Palette, Right-click, Dbl-click, Shift+click.
Renamed from "Quick start" to "Shortcuts & tips".
- canvas-audit-items.md: update Keyboard Shortcuts section from PARTIAL
to complete; mark help dialog item as done.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>