3015

Fixed

• Boot step "Initializing game importer" disproportionately slow — Multiple optimizations to the game importer initialization path:
  1. initCorePlists() now has an idempotency guard so the redundant second call from initSystems() returns instantly when the background pre-fire has already completed.
  2. Per-system directory creation (createDefaultDirectories) moved to a background Task.detached — filesystem I/O for 60+ system ROM folders no longer blocks the boot sequence.
  3. updateSystemToPathMap() simplified from an async-reduce with actor hops to a synchronous loop, eliminating unnecessary context switches.
  4. Removed unused updateromExtensionToSystemsMap() function that was dead code inside initSystems().
  5. CoreLoader.getCorePlists() runs in a detached task with full-result disk caching so subsequent launches skip the filesystem scan entirely.