feat(studio): bake WebAudio synth into offline audio tracks for Codex Tetris

[miguel-heygen]

Summary

• WebAudio synth (oscillators, noise channels) can't be captured by the headless renderer — it only processes file-based <audio> tracks via FFmpeg during the audio stage
• Added bake-audio.ts that pre-renders chiptune BGM and SFX offline into WAV files using square/triangle wave oscillator math — no external deps, just bun run bake-audio.ts
• Composition references the baked WAVs as standard <audio> elements with data-start/data-duration/data-volume, so the producer pipeline picks them up normally

Composition

1080×1920 vertical, 28s, 4 scenes:

1. QR scan — phone mockup with deterministic QR grid, CRT scanlines, phosphor green glow
2. Console boot — CODEX GAMING system loading bar
3. Tetris gameplay — 10×20 board, 4 falling pieces with Penrose cursor AI, line clear flashes, score/lines/level counters
4. Game over + attribution — final score, @HyperFrames_ / @Miguel07Code

Transitions: glitch (primary, 2×) + chromatic aberration (accent, 1×)

Test plan

• bun run bake-audio.ts generates valid bgm.wav and sfx.wav (28s PCM WAV each)
• npx hyperframes lint passes with 0 errors
• npx hyperframes validate --no-contrast passes with no console errors
• Preview in studio shows all 4 scenes with transitions and falling pieces
• Render to MP4 includes both audio tracks in the final mix