Theme:
- Replace green felt table with dark navy (#0f1623) matching app identity
- Gold accent (#E4AC38) replaces green for highlights and UI elements
- Tiles have warm ivory (#F5F0E8) with subtle shadows on dark bg
- All UI bars/controls use app's #0f0f1e background

Layout engine rewrite:
- Chain starts from center, grows outward naturally
- Proper double placement (perpendicular to chain direction)
- Non-doubles align correctly with chain direction
- Snake path with smooth turns at virtual bounds

Interaction (tap-to-confirm):
- Tap tile → highlights valid endpoints on board
- Tap highlighted endpoint → confirms placement
- NEVER auto-places on tap — always requires explicit destination
- Tap same tile again → deselects it
- Status shows "اختر مكان الوضع" when tile is selected

Board improvements:
- Pan gesture: drag on empty board area to scroll
- Auto-zoom: smoothly zooms out as chain grows large
- Endpoint glow uses gold dashed-ring indicator
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>