- Refactor cause in draw_game_over_screen to an immediately invoked lambda, eliminating dead store warning
- Rename sound effect files to standard-compliant names without double underscores to prevent reserved macro warnings in soundbank.h
- Update source/game_audio.cpp to use clean SFX_* macro identifiers
- Add codechecker_skip.txt to ignore external devkitPro toolchain headers
- Ignore .codechecker/ output artifacts directory in .gitignore
- Update AGENTS.md file tree and sound asset references
