Files
hyperframes/packages
Varo b390b71bde fix(engine): keep BeginFrame time monotonic across frame rates (#3011)
Fixes #3012

## What

Fixes `HeadlessExperimental.beginFrame` hanging at 60fps and other high frame rates.

## Why

Warmup always advances Chrome in 33ms steps, but the first capture timestamp was calculated from the output fps.

At 60fps, the last warmup tick is 1947ms, while the next commit tick used to jump back to about 1067ms. Chrome sees time moving backwards and `beginFrame` can stall.

## How

Keep the old timestamps when they are already safe. If the commit tick would go backwards, move the capture baseline past warmup first.

The init commit and both producer probes now use the same timestamp helpers, so they cannot calculate different values.

## Test plan

- [x] Added tests for 24, 30, 31, 32, 33, 60, 120, 240, and 59.94fps
- [x] Added coverage for the actual session baseline, commit parameters, and both producer probe paths
- [x] Engine tests: 1383 passed, 3 skipped
- [x] Producer unit tests passed
- [x] Engine and producer typechecks and builds passed
- [ ] Manual render test
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