When the pause button was added below the rink, it increased the canvas
height (RINK_HEIGHT + UI_BOTTOM_PADDING). The coordinate conversion was
incorrectly using the full canvas center (including UI padding) instead
of just the rink center, causing y=0 to shift 30 pixels below the actual
center of the rink.
Now CoordinateUtils.gameToScreen/screenToGame correctly use RINK_WIDTH
for centerY calculation, ensuring y=0 is always at the rink center
regardless of UI elements.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
