20260524 update — MineSweeper Rush Steam update #716781

1. Fixed music loading and playback issues: Improved MIDI music detection, loading, and playback handling. This reduces the chance of invalid playback behavior when MIDI support is unavailable or when music files fail to load correctly. 2. Fixed a Steam achievement constant: Corrected the achievement constant for CUM_DEAD_1000, preventing the wrong achievement from being checked or unlocked when death-count progress is updated. 3. Fixed Steam leaderboard handling: Improved leaderboard handle validation and recovery. Leaderboards should now load, display, and update more reliably when Steam fails to return a valid leaderboard handle on the first attempt. 4. Fixed line-adding logic: Corrected edge cases in the new-line generation process, including situations related to Relax Mode, mask rows, and automatic line updates after mine triggers or full-grid events. 5. Fixed graphics resource cle...