Custom DarkButton component with Dracula theme colors:
- bg-secondary base, button-hover on hover
- primary variant with accent-purple
- Disabled state with reduced opacity
- Consistent 28px height, 4px border-radius
Also fixes PickDarkButton/KeyDarkButton naming errors from agent.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>