Move the required game.db resource resolution and ETI catalog loading out of
Tauri setup into small helpers. The setup closure now describes the startup
flow instead of carrying resource-resolution and conversion details inline.
This keeps the existing fail-fast behavior for a missing or unreadable bundled
catalog, while giving the required resource path and in-memory GameDB conversion
clear names. There is no intended user-visible behavior change.
Test Plan:
- cargo clippy
- cargo clippy --benches
- cargo clippy --tests
- cargo +nightly fmt
Refs: none
ddidderr
5480d1bdd4
