The board was empty because:
1. Scripts cached from previous nav resolved immediately
2. Board/Game singletons kept stale DOM references
3. Race condition between DOM render and script execution

Fix:
- Remove existing script tags before re-adding (forces re-execution)
- Load scripts SEQUENTIALLY (chess.min → openings → board → game)
- requestAnimationFrame before script loading (DOM settle)
- Explicit document.getElementById('board') check before Board.init
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>