Replace all user-facing "note(s)" with "crumb(s)" — sidebar, search
placeholder, editor placeholders, empty states. Use Lucide icons
(StickyNote, Archive, Trash2, Tag) in sidebar for consistency.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Remove ThemeToggle component, theme store, dark: Tailwind variants,
and dark color values from NOTE_COLORS. Simplify color logic to use
a single bg property. Delete dark mode e2e tests.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
