Optimization: Late-game saves can now be completed in about 1 second.

Optimization: Optimized save speed so late-game saves can now complete in about 1 second.
Bug Fix: Fixed an issue where warship group IDs were not saved, causing them to reset after loading.
Optimization: Fixed an issue where residual files left after deleting certain MODs could cause the game to incorrectly detect MODs as installed, disabling leaderboard features.