diff --git a/.claude-plugin/plugin.json b/.claude-plugin/plugin.json
index 7b6d1ab784..cf4f0c1468 100644
--- a/.claude-plugin/plugin.json
+++ b/.claude-plugin/plugin.json
@@ -1,7 +1,7 @@
 {
   "name": "hyperframes",
   "description": "HyperFrames by HeyGen. Write HTML, render video. Compositions, GSAP and runtime adapter animations, captions, voiceovers, audio-reactive visuals, and website capture for HyperFrames.",
-  "version": "0.8.41",
+  "version": "0.8.42",
   "author": {
     "name": "HeyGen",
     "email": "hyperframes@heygen.com",
diff --git a/.codex-plugin/plugin.json b/.codex-plugin/plugin.json
index 889e64fec5..45d25dfefc 100644
--- a/.codex-plugin/plugin.json
+++ b/.codex-plugin/plugin.json
@@ -1,7 +1,7 @@
 {
   "name": "hyperframes",
   "description": "Write HTML, render video. Compositions, Tailwind v4 styles, GSAP and runtime adapter animations, captions, voiceovers, audio-reactive visuals, and website capture for HyperFrames.",
-  "version": "0.8.41",
+  "version": "0.8.42",
   "author": {
     "name": "HeyGen",
     "email": "hyperframes@heygen.com",
diff --git a/.cursor-plugin/plugin.json b/.cursor-plugin/plugin.json
index 1fa709b2d0..8b96462fa2 100644
--- a/.cursor-plugin/plugin.json
+++ b/.cursor-plugin/plugin.json
@@ -3,7 +3,7 @@
   "name": "hyperframes",
   "displayName": "HyperFrames by HeyGen",
   "description": "Write HTML, render video. Compositions, Tailwind v4 styles, GSAP and runtime adapter animations, captions, voiceovers, audio-reactive visuals, and website capture for HyperFrames.",
-  "version": "0.8.41",
+  "version": "0.8.42",
   "author": {
     "name": "HeyGen",
     "email": "hyperframes@heygen.com"
diff --git a/docs/changelog.mdx b/docs/changelog.mdx
index 6f4b366cd0..6fae279c17 100644
--- a/docs/changelog.mdx
+++ b/docs/changelog.mdx
@@ -8,6 +8,28 @@ Recent HyperFrames releases, including user-facing features, fixes, and migratio
 
 {/* New release entries are prepended by `bun run changelog:draft <version> --write`. */}
 
+<Update
+  label="HyperFrames v0.8.42"
+  description="Released - 2026-09-16"
+  tags={["Release", "CLI", "Engine", "Studio Server"]}
+>
+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)).
+
+[View the full commit range](https://github.com/heygen-com/hyperframes/compare/v0.8.41...v0.8.42).
+</Update>
+
 <Update
   label="HyperFrames v0.8.41"
   description="Released - 2026-09-15"
diff --git a/packages/aws-lambda/package.json b/packages/aws-lambda/package.json
index 2e6166969b..9bff161e0d 100644
--- a/packages/aws-lambda/package.json
+++ b/packages/aws-lambda/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/aws-lambda",
-  "version": "0.8.41",
+  "version": "0.8.42",
   "description": "AWS Lambda adapter for HyperFrames distributed rendering — handler, client-side SDK, and CDK construct.",
   "repository": {
     "type": "git",
diff --git a/packages/cli/package.json b/packages/cli/package.json
index 39866d7a34..d3cefc3895 100644
--- a/packages/cli/package.json
+++ b/packages/cli/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/cli",
-  "version": "0.8.41",
+  "version": "0.8.42",
   "description": "HyperFrames CLI — create, preview, and render HTML video compositions",
   "license": "Apache-2.0",
   "repository": {
diff --git a/packages/core/package.json b/packages/core/package.json
index fd055e042c..4924a836bd 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/core",
-  "version": "0.8.41",
+  "version": "0.8.42",
   "description": "",
   "repository": {
     "type": "git",
diff --git a/packages/engine/package.json b/packages/engine/package.json
index dd4b3935d2..6a0305bcd9 100644
--- a/packages/engine/package.json
+++ b/packages/engine/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/engine",
-  "version": "0.8.41",
+  "version": "0.8.42",
   "description": "Seekable web page to video rendering engine (Puppeteer + FFmpeg)",
   "repository": {
     "type": "git",
diff --git a/packages/gcp-cloud-run/package.json b/packages/gcp-cloud-run/package.json
index 58e5c9c4ec..08d18fdff9 100644
--- a/packages/gcp-cloud-run/package.json
+++ b/packages/gcp-cloud-run/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/gcp-cloud-run",
-  "version": "0.8.41",
+  "version": "0.8.42",
   "description": "Google Cloud Run + Workflows adapter for HyperFrames distributed rendering — request handler, client-side SDK, and Terraform module.",
   "repository": {
     "type": "git",
diff --git a/packages/lint/package.json b/packages/lint/package.json
index 7a6f7e34a3..48858dcb4b 100644
--- a/packages/lint/package.json
+++ b/packages/lint/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/lint",
-  "version": "0.8.41",
+  "version": "0.8.42",
   "repository": {
     "type": "git",
     "url": "https://github.com/heygen-com/hyperframes",
diff --git a/packages/parsers/package.json b/packages/parsers/package.json
index c14d456649..9267a32c10 100644
--- a/packages/parsers/package.json
+++ b/packages/parsers/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/parsers",
-  "version": "0.8.41",
+  "version": "0.8.42",
   "repository": {
     "type": "git",
     "url": "https://github.com/heygen-com/hyperframes",
diff --git a/packages/player/package.json b/packages/player/package.json
index a5099bff28..7f935992a6 100644
--- a/packages/player/package.json
+++ b/packages/player/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/player",
-  "version": "0.8.41",
+  "version": "0.8.42",
   "description": "Embeddable web component for HyperFrames compositions",
   "repository": {
     "type": "git",
diff --git a/packages/producer/package.json b/packages/producer/package.json
index 7fb4de453a..76e817f52e 100644
--- a/packages/producer/package.json
+++ b/packages/producer/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/producer",
-  "version": "0.8.41",
+  "version": "0.8.42",
   "description": "HTML-to-video rendering engine using Chrome's BeginFrame API",
   "repository": {
     "type": "git",
diff --git a/packages/sdk/package.json b/packages/sdk/package.json
index 25219a0a65..32a1c874fd 100644
--- a/packages/sdk/package.json
+++ b/packages/sdk/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/sdk",
-  "version": "0.8.41",
+  "version": "0.8.42",
   "description": "Headless, framework-neutral HyperFrames composition editing engine",
   "repository": {
     "type": "git",
diff --git a/packages/shader-transitions/package.json b/packages/shader-transitions/package.json
index a2ed24f33a..4d7b999da4 100644
--- a/packages/shader-transitions/package.json
+++ b/packages/shader-transitions/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/shader-transitions",
-  "version": "0.8.41",
+  "version": "0.8.42",
   "description": "WebGL shader transitions for HyperFrames compositions",
   "repository": {
     "type": "git",
diff --git a/packages/studio-server/package.json b/packages/studio-server/package.json
index 30c6fc05ef..f6adbd9473 100644
--- a/packages/studio-server/package.json
+++ b/packages/studio-server/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/studio-server",
-  "version": "0.8.41",
+  "version": "0.8.42",
   "repository": {
     "type": "git",
     "url": "https://github.com/heygen-com/hyperframes",
diff --git a/packages/studio/package.json b/packages/studio/package.json
index d141cea9ad..11b28007c7 100644
--- a/packages/studio/package.json
+++ b/packages/studio/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@hyperframes/studio",
-  "version": "0.8.41",
+  "version": "0.8.42",
   "description": "",
   "repository": {
     "type": "git",
diff --git a/releases/v0.8.42.md b/releases/v0.8.42.md
new file mode 100644
index 0000000000..8a00d306e4
--- /dev/null
+++ b/releases/v0.8.42.md
@@ -0,0 +1,21 @@
+# 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