bug: hf-seek events from Three.js adapter may not reach user listeners during Puppeteer render

[gumibera]

Description

The Three.js adapter dispatches CustomEvent("hf-seek") on window during its seek() method, but user script window.addEventListener("hf-seek", ...) listeners may not receive these events during Puppeteer frame capture (render mode).

Expected behavior

Compositions using the /three skill pattern should receive hf-seek events and render their Three.js scene at each frame time.

Actual behavior

The hf-seek listener never fires. The Three.js scene either remains static (if preserveDrawingBuffer: true is set) or renders blank (if not).

window.__hfThreeTime IS set correctly — the adapter's seek() executes, but the event dispatch (wrapped in try/catch at packages/core/src/runtime/adapters/three.ts) may silently fail.

Reproduction

1. Create a composition using only the hf-seek event pattern from skills/three/SKILL.md
2. Add preserveDrawingBuffer: true to the renderer (otherwise output is blank regardless)
3. Render with npx hyperframes render
4. Observe: Three.js canvas is static in the output

Workaround

Hook into the GSAP timeline's onUpdate callback instead:

tl.eventCallback("onUpdate", () => {
  renderAt(tl.time());
});

This works because HyperFrames seeks GSAP timelines directly via timeline.totalTime(), which fires onUpdate on every frame. Documented in #583.

Root cause hypothesis

The adapter's seek() is called during onDeterministicSeek (init.ts) which runs during renderSeek. The user script's event listener may be registered in a different execution context, or the event dispatch may be swallowed by the try/catch that wraps window.dispatchEvent().

Environment

• HyperFrames: latest (via npx)
• macOS, Node 25, Chrome (Puppeteer bundled)
• Three.js r128 (global build)

Discovered by 0xHoneyJar using the Loa framework.

[miguel-heygen]

good catch!