Audio integration

[Otaiki1]

Overview

Add a full in-game audio layer — sound effects for all major game events, optional background music, and persistent volume settings.

Sound Effects

Event	Sound	Trigger
Piece selected	Soft click (50ms)	Tray hit in handleStart
Piece placed	Thud/knock (120ms)	Successful placePiece()
Line clear	Swoosh + chime (350ms)	Each row/col cleared
Multi-clear (2+ lines)	Layered swoosh, brighter chime	linesCleared >= 2 in one move
Combo trigger	Bass hit + ring (400ms)	newComboStreak > 0 with lines cleared
UNSTOPPABLE tier	Power-up fanfare (600ms)	Combo streak reaches 7
Game over	Descending tone (500ms)	isGameOver becomes true
Score submitted	Success jingle (800ms)	On-chain submission confirmed
Revival purchased	Coin sound (300ms)	Revive confirmed
Button tap	Subtle UI click (30ms)	All brutal-btn presses

Background Music

• Off by default, toggled in Settings
• Single ambient loop during gameplay
• Pauses when pause menu is open
• Recommended: "Sneaky Snitch" by Kevin MacLeod (CC BY 4.0) or equivalent 120–135 BPM loop

Volume Controls

Two sliders in Settings:

• Sound Effects — persisted to localStorage key blokaz:sfx_volume
• Music — persisted to localStorage key blokaz:music_volume

Implementation

• src/audio/AudioManager.ts — singleton with play(event), setMusicVolume(v), setSfxVolume(v), pauseMusic(), resumeMusic()
• Web Audio API directly (no library) for low-latency SFX
• Lazy initialisation on first user gesture (browser autoplay policy)
• Audio files in public/sounds/ as MP3, <50KB each
• MiniPay: haptic navigator.vibrate() calls remain — audio is complementary

Files to Change

• src/audio/AudioManager.ts — new singleton
• src/components/GameScreen.tsx — call AudioManager.play(event) at each game event
• src/components/LobbyScreen.tsx — button click audio
• Settings screen — volume sliders
• public/sounds/ — audio files

Contract change required: No