Preserving the entry extensions field through v2 char exports and imports

public/scripts/world-info.js

@@ -4565,6 +4565,7 @@ function convertCharacterBook(characterBook) {
             sticky: entry.extensions?.sticky ?? null,
             cooldown: entry.extensions?.cooldown ?? null,
             delay: entry.extensions?.delay ?? null,
+            extensions: entry.extensions ?? {},
         };
     });
 

src/endpoints/characters.js

@@ -468,6 +468,7 @@ function convertWorldInfoToCharacterBook(name, entries) {
             position: entry.position == 0 ? 'before_char' : 'after_char',
             use_regex: true, // ST keys are always regex
             extensions: {
+                ...entry.extensions,
                 position: entry.position,
                 exclude_recursion: entry.excludeRecursion,
                 display_index: entry.displayIndex,