retroarch.yml regenerated by libretro_scraper with CORE_SUBDIR_MAP
(dc/, np2kai/, keropi/) and shared groups (fuse, kronos, ep128emu,
quasi88, np2kai, keropi). common.py dedup by (name, destination)
to allow same file at flat + subdirectory paths.
ep128emu shared group added for Enterprise system.
RetroArch pack grows from 398 to 428 files.
ref: each subdirectory traced to original emulator source code —
see platforms/README.md and _shared.yml comments.