v0.8.42

# HyperFrames v0.8.42

Released on 2026-09-16.

Studio preview and render downloads now work for compositions and files with non-Latin-1 names. Forced `--sdr` renders tone-map HDR sources so colors match the Studio preview. HDR auto-promotion now shows up in `check --json`, and render workers no longer survive as orphans after Ctrl-C or a parent exit.

## Fixes

- **CLI:** Stop render and preview worker processes from surviving as orphans after Ctrl-C, parent exit, or a stopped Windows wrapper. Carry cancellation through final artifact promotion so a cancelled render never replaces an existing output. Set `HYPERFRAMES_RENDER_DETACHED=1` for intentionally detached renders ([08d48ab75](https://github.com/heygen-com/hyperframes/commit/08d48ab7539e3a21facbe005c0610f2dbc8bf5a5), [#3974](https://github.com/heygen-com/hyperframes/pull/3974)).
- **Engine:** Tone-map HDR sources before frame extraction on forced `--sdr` renders, fixing the cool color cast versus the Studio preview ([ef48485b9](https://github.com/heygen-com/hyperframes/commit/ef48485b919c69735659a09dc01aa21aa73a4f51), [#3981](https://github.com/heygen-com/hyperframes/pull/3981)).
- **CLI:** Report HDR auto-promotion in `check --json` with the triggering asset and resulting output pipeline, and print one render warning when it fires ([5d2478c6f](https://github.com/heygen-com/hyperframes/commit/5d2478c6fae413f28c6106ca4359b952e7434a50), [#3985](https://github.com/heygen-com/hyperframes/pull/3985)).
- **Studio Server:** Serve render downloads and file responses for non-Latin-1 filenames using RFC 6266 `Content-Disposition` headers ([b599f031a](https://github.com/heygen-com/hyperframes/commit/b599f031a929f55ade71246a7b3c5701b311aa46), [#3984](https://github.com/heygen-com/hyperframes/pull/3984)).
- **Studio Server:** Fix a Studio preview server crash for compositions whose file path contains non-Latin-1 characters by hashing sub-composition paths into ASCII-safe ETags ([edb6e87ba](https://github.com/heygen-com/hyperframes/commit/edb6e87ba7fa8fa49039dc4ccbe5733cf58afdae), [#3982](https://github.com/heygen-com/hyperframes/pull/3982)).

## Internal

- **Engine:** Cover held tails in HDR preflight ([ae18e3a32](https://github.com/heygen-com/hyperframes/commit/ae18e3a327e66e18747cdcc7b4a16b20ea75f97a), [#3963](https://github.com/heygen-com/hyperframes/pull/3963)).

## Full changelog

https://github.com/heygen-com/hyperframes/compare/v0.8.41...v0.8.42