Mod Features and Save Files

cc @tellowkrinkle
cc @orian34 in case you have found any related issues.

A number of modded features were designed without individual game save files in mind. For example, I created a little mod for myself recently to play back the most recent voice, storing it in memory, but after a quick load the last voice isn't remembered. We had to add state for lip sync and sprite switching etc. but I don't believe any of it is persisted besides the flags, so there may be unexpected behavior when someone boots up the game again and loads a save file in the middle of a scene. I have a feeling this is related to the issue of people seeing double sprites. Let's investigate this.

(Btw, global flags are persisted automatically without respect to save files, so that's separate.)

The issue mentions mod features like voice playback, lip sync, and sprite switching that may not persist across save files. Start by examining how game state is saved and loaded, particularly for modded components. Look for existing state management code related to flags and scene persistence. Determine what 'done' looks like by testing if mod features retain state after a save/load cycle.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.