3516

Added

• Gambatte rcheevos integration — Wire GB/GBC native RetroAchievements via the shared PVRcheevos SPM package (CRcheevos); enable HAVE_RCHEEVOS in PVGambatteBridge; implement full rc_client lifecycle with NSURLSession server call and credential-based login.
• libgambatte patch documentation — PATCHES.md + unified diff in Sources/libgambatte/patches/ documenting all upstream modifications for reproducibility when updating gambatte.