fix(desktop): suspend idle poof audio context

[yinkev]

Summary

• disconnect each poof sound's AudioBufferSourceNode and GainNode when playback ends, keeping the WebAudio graph flat
• suspend the singleton AudioContext 1.5 seconds after the final sound and cancel that idle suspension when another poof starts
• serialize replay against an already in-flight suspend() so rapid clicks resume cleanly instead of starting into a newly suspended context
• preserve the existing HTML audio fallback when graph creation, context resume, or source start fails, while rearming idle suspension after a failed graph setup

This stays focused on the measured lifecycle leak. Sample-rate policy, offline decoding, and a native-audio rewrite remain separate work.

Related issue

Fixes #2868.

Closest existing PR: #2804 changes the poof asset codec for Linux decoding; this PR is orthogonal and fixes the context/node lifetime after playback.

Testing

• pnpm check
• pnpm typecheck
• focused poof lifecycle tests — 8 passed
• full desktop unit suite — 3,512 passed
• desktop production build — passed

No visual changes.

[yinkev]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. 🚀

Reviewed commit: 9dc4602964

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[yinkev]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Keep it up!

Reviewed commit: 3675d5059c

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[FabianHertwig]

Thanks for picking this up — the node-disconnect plus debounced-suspend logic reads right for the lifecycle the issue describes. Flagging one path I don't think it covers, based on macOS measurements I've just posted on #2868.

scheduleSuspend() is only reachable from play() — the graph-creation catch and cleanup() when the last playback ends. That holds if the context can only reach running via playPoofSound() → resume().

On macOS it can't: when the embedder allows autoplay (the webview default Buzz takes), a freshly constructed AudioContext auto-resumes to running on its own, with no user gesture and nothing played. I isolated it in a minimal WKWebView host — A/B table and log trace are in #2868. The short version from a real launch:

13:11:25.996  RemoteAudioDestination::RemoteAudioDestination(…)   ← the AudioContext
13:11:26.004  coreaudiod  Take: …BuiltInSpeakerDevice.context.preventuseridlesleep on behalf of 79092
13:11:26.035  RemoteAudioDestination::start(…)                    ← went running by itself

Since PoofBurstProvider's mount effect calls loadPoofAudioBuffer() → getPoofAudioContext() at startup just to decode the asset, that means the context is constructed on every launch, goes running moments later, play() is never called, scheduleSuspend() never runs, and the output device stays pinned for the whole session. Measured here: no idle sleep for 12.5 h and battery 38% → 1% overnight, without a single poof.

One wrinkle if you do arm the suspension at construction: a plain scheduleSuspend(context) there would race the auto-resume — the timer fires at 1.5 s, sees state === "suspended", and returns; the context then flips to running at ~2 s and stays. Keying on statechange sidesteps the ordering:

// in createPoofAudioPlayer(), alongside play()
function armIdleSuspend(context: AudioContext) {
  // WebKit returns a suspended context but auto-resumes it when the embedder
  // allows autoplay, so an idle context can reach "running" with no playback.
  // Re-arm on every transition instead of assuming play() is the only path.
  context.addEventListener("statechange", () => {
    if (context.state === "running" && activePlaybacks === 0) {
      scheduleSuspend(context);
    }
  });
  if (context.state === "running") scheduleSuspend(context);
}

return { armIdleSuspend, play };

called once where the singleton is created:

function getPoofAudioContext() {
  try {
    if (!poofAudioContext) {
      poofAudioContext = new AudioContext({ latencyHint: "interactive" });
      poofAudioPlayer.armIdleSuspend(poofAudioContext);
    }
    return poofAudioContext;
  } catch {
    return null;
  }
}

This composes with what you already have rather than duplicating it: play() calls cancelPendingSuspend() first, and activePlaybacks is incremented before resume(), so the statechange from a real poof can't schedule a suspension mid-playback; cleanup() still owns the post-playback case; and suspend() itself fires one more statechange that no-ops. The first poof after startup finds a suspended context, which resumeThenStart() already handles.

The alternative is to not construct a hardware context at startup at all — decode via OfflineAudioContext, which never binds an output device, and create the real context on the first poof. That's the offline-decoding work you scoped out of this PR, so the statechange arming above is probably the smaller move here.

Happy to test either against my setup — the assertion is directly observable via pmset -g assertions | grep -A2 BuiltInSpeakerDevice, so it's a clean pass/fail.

[yinkev]

Thanks for the concrete WebKit trace. Addressed in the latest commit: the singleton now arms an idle-suspend statechange listener when the AudioContext is created, so an autoplay-enabled context that transitions to running without any poof is suspended after the debounce. Active playback still cancels the timer before resume, and the listener only arms while there are zero active playbacks. Added a focused suspended → auto-running regression; the poof lifecycle suite passes 8/8.