Final Scene gameplay polish and targeting fixes

[LevelX2]

Summary

• improve bow projectile visuals, timing, and audio feedback
• refine door/key visuals and adjacent door interaction controls
• allow visible ranged targets behind strong corner cover with appropriate hit chance penalties
• stabilize step sound playback after suspended audio context resume
• add and update module/E2E coverage plus project knowledge log entries

Verification

• npm run verify
• npm run check:memory