Add mini board previews using tenuki on games list
- Created MiniBoard.svelte component using tenuki for small board previews
- Added tenuki TypeScript declarations (tenuki.d.ts)
- Integrated mini boards into current games list (both logged-in and spectating views)
- Fetches moves for active games and displays current board state
- Fixed og-image to use correct tenuki API (intersectionAt instead of intersections)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>