- Created bookmark_portraits/ with placeholder portrait definitions
for all 4 bookmark characters (regenerate in-game with
dump_bookmark_portraits for proper visuals)
- Added bm_group_1020 bookmark group and localization
- Added start_date to vanilla bookmark suppression entries (required
field per ck3-tiger)
- Removed invalid background field from bookmark definition
- Added replace_path directives for bookmarks to mod descriptors
- Adjusted character positions on the bookmark screen
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>