b2f875c5a5
Add visual arrow connecting borrow box to borrowed 10s box: - Straight diagonal line from top of borrow box - Points to center of borrowed 10s box below - White line (1.5pt) on colored backgrounds - Gray line on non-colored backgrounds - Coordinates: (0, 0) to (0.24×cellSize, 0.75×cellSize) Arrow appears when showBorrowingHints toggle is enabled. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>