generate_db.py now reads aliases from emulator YAMLs and indexes
them in database.json by_name. resolve_local_file in common.py
tries all alias names when the primary name fails to match.
beetle_psx alt_names renamed to aliases (was not indexed before).
snes9x BS-X.bios, np2kai FONT.ROM/ide.rom/pci.rom fallbacks,
all now formally declared as aliases and indexed.
verify --all and generate_pack --all pass with 0 regressions.