Show HN: Fast Sudoku solver that enumerates all solutions (sudoku-solver.piyochan.jp)

Hi HN, I built a Sudoku solver web app focused on speed and correctness.

It solves standard puzzles quickly, but it can also handle ambiguous puzzles: instead of stopping at the first solution, it enumerates all valid solutions and reports the total number of solutions.

I built it mainly to explore performance and edge cases. Feedback is welcome!