Migrations:
- 016, 017, 019: Replace gen_random_uuid() with uuid_generate_v7()
- All UUID tables now use custom uuid_generate_v7() function
Backend:
- Create internal/utils/uuid/uuid.go with V7() function (RFC 9562)
- Update storage_handler.go to use internal uuid.V7()
- Remove dependency on google/uuid for file naming
All new UUIDs in the system are now UUID v7 (time-ordered)