## Problem
`wrapScopedCompositionScript` wraps composition scripts with scoped `document`, `window`, and `gsap` proxies. The current published `latest` and `alpha` packages still pass the proxy as the `Reflect.get` receiver, so browser host accessors like `document.body` can throw `TypeError: Illegal invocation`.
When that happens, the wrapper catches the error and aborts the rest of the composition script. For components that start hidden and reveal themselves through GSAP/timeline setup, that means the timeline is never registered and the render can stay visually empty.
Closes#606.
## What this fixes
- Reads scoped proxy properties with the original target as the `Reflect.get` receiver.
- Applies the same target-receiver pattern to scoped proxy setters, including remapped timeline registry writes.
- Preserves the existing behavior of binding returned methods back to the real target.
- Covers document, window, remapped timeline registry, GSAP, and GSAP utils accessors/setters in regression tests that throw unless the receiver is the original target.
## Root cause
The previous proxy traps called `Reflect.get(target, prop, receiver)`. For accessors, that invokes the getter with `this === receiver`, and in this wrapper the receiver is the proxy. Browser host getters such as `Document.prototype.body` validate their receiver and reject the proxy, which makes ordinary composition code like `document.body` fail before timeline registration can run.
## Verification
### Local checks
- Confirmed current npm state with `npm view @hyperframes/core version dist-tags versions --json` and `npm view @hyperframes/producer version dist-tags versions --json`: `latest` is `0.4.42`, `alpha` is `0.5.0-alpha.14`.
- Packed `@hyperframes/core` and `@hyperframes/producer` at both `latest` and `alpha`; all four packed artifacts still contained the bad `Reflect.get(target, prop, receiver)` / `utilsReceiver` wrapper patterns before this fix.
- `bun run --cwd packages/core test -- src/compiler/compositionScoping.test.ts`
- `bunx oxlint packages/core/src/compiler/compositionScoping.ts packages/core/src/compiler/compositionScoping.test.ts`
- `bunx oxfmt --check packages/core/src/compiler/compositionScoping.ts packages/core/src/compiler/compositionScoping.test.ts`
- `bun run --cwd packages/core build`
- `bun run --cwd packages/core typecheck`
- `bun run --cwd packages/producer typecheck`
- `bun run --cwd packages/producer build`
- `bun test packages/producer/src/services/htmlCompiler.test.ts`
- Confirmed the rebuilt core runtime and producer bundles no longer contain the old `Reflect.get(..., receiver)` / `Reflect.set(..., receiver)` scoped-wrapper patterns.
- `git diff --check`
- Pre-commit also reran lint, format, and typecheck successfully.
### Browser verification
Used `agent-browser` against generated local repro pages:
- `core latest 0.4.42`: `bodyRead: false`, `titleOpacity: "0"`, `timelineRegistered: false`, `errorCount: 1`
- `core alpha 0.5.0-alpha.14`: `bodyRead: false`, `titleOpacity: "0"`, `timelineRegistered: false`, `errorCount: 1`
- Patched local wrapper: `bodyRead: true`, `titleOpacity: "1"`, `timelineRegistered: true`, `errorCount: 0`
## Notes
- Browser screenshots and the `agent-browser` recordings are local-only under `tmp/issue-606/browser/`, including `issue-606-browser-proof.webm` and `issue-606-after-comment.webm`.
- No generated `dist/` artifacts are committed.
## Problem
Studio frame capture could fail for projects mounted outside the repo when the project id came from an encoded hash route. A project like `Notion Showcase` loaded as `#project/Notion%20Showcase`, but the capture URL encoded that already-encoded value again, producing `/api/projects/Notion%2520Showcase/...` and a 404.
While validating the fix by seeking through the preview, capture also diverged from the visible player for nested compositions because the thumbnail route sought raw timelines instead of the same player seek path used by Studio preview.
## What this fixes
- Decodes project ids when reading Studio `#project/...` routes and centralizes project hash/API path construction.
- Keeps API URLs encoded exactly once, including project names with spaces, literal `%`, reserved characters, and unicode.
- Updates Studio thumbnail capture to prefer `window.__player.seek(t)` and only fall back to raw timeline seeking for standalone pages.
- Preserves explicit `t=0` thumbnail requests instead of falling back to `0.5` seconds.
- Adds preview-regression CI coverage for Studio routing, frame capture URL construction, thumbnail seeking, and core thumbnail seek parsing.
## Root cause
Studio treated the hash route segment as the canonical project id even when the browser had already percent-encoded it. `buildFrameCaptureUrl` then encoded that string again, so a decoded project directory name and the capture API path no longer matched.
The preview/capture mismatch was a separate seek-path issue: the visible Studio preview seeks through the HyperFrames player, which maps global time into nested composition time. The capture route bypassed that layer and paused all registered timelines at the same global time.
The zero-second capture case came from parsing `t` with a truthiness fallback, so `parseFloat("0") || 0.5` became `0.5`.
## Verification
### Local checks
- `bun run --cwd packages/studio test -- vite.thumbnail.test.ts src/utils/projectRouting.test.ts src/utils/frameCapture.test.ts`
- `bun run --cwd packages/core test -- src/studio-api/routes/thumbnail.test.ts`
- `bunx oxfmt --check .github/workflows/preview-regression.yml packages/studio/vite.thumbnail.ts packages/studio/vite.thumbnail.test.ts packages/studio/vite.config.ts packages/studio/src/utils/projectRouting.ts packages/studio/src/utils/projectRouting.test.ts packages/studio/src/utils/frameCapture.ts packages/studio/src/App.tsx packages/core/src/studio-api/routes/thumbnail.ts packages/core/src/studio-api/routes/thumbnail.test.ts`
- `bunx oxlint .github/workflows/preview-regression.yml packages/studio/vite.thumbnail.ts packages/studio/vite.thumbnail.test.ts packages/studio/vite.config.ts packages/studio/src/utils/projectRouting.ts packages/studio/src/utils/projectRouting.test.ts packages/studio/src/utils/frameCapture.ts packages/studio/src/App.tsx packages/core/src/studio-api/routes/thumbnail.ts packages/core/src/studio-api/routes/thumbnail.test.ts`
- `bun run --cwd packages/studio typecheck`
- `bun run --cwd packages/core build:hyperframes-runtime`
- `bun run --cwd packages/core typecheck`
- `git diff --check`
Pre-commit also reran lint, format, and typecheck successfully for the committed files.
### Browser verification
Using `agent-browser`, I mounted `/Users/miguel07code/Downloads/Notion Showcase` into Studio's project data and opened:
```text
http://127.0.0.1:5197/#project/Notion%20Showcase
```
Before the fix, Capture requested `/api/projects/Notion%2520Showcase/thumbnail/index.html?...` and Studio showed `Capture failed`.
After the fix, I sought the preview to `0s`, `2s`, `10s`, and `18s`, captured each frame, and compared the visible preview crop against the capture output. The capture URLs all used `Notion%20Showcase`, not `Notion%2520Showcase`, and no failure toast appeared.
Mean pixel diffs for preview vs capture were:
- `0s`: `0.0`
- `2s`: `0.8641`
- `10s`: `0.3496`
- `18s`: `0.2309`
The small non-zero diffs are raster/antialias-level differences after resizing the capture to the preview crop dimensions.
## Notes
- Browser screenshots, comparison sheets, network logs, and the `agent-browser` recording are local-only under `qa-artifacts/capture-button/` and are not committed.
- The local Notion Showcase project mount is an ignored symlink under `packages/studio/data/projects/` and is not committed.
- Thumbnail cache versions were bumped so stale captures generated with the old seek behavior are not reused.
## Problem
I reproduced the selected open issue batch one by one and confirmed the reports were valid. The fixes all touch the CLI/runtime capture boundary, then the follow-up regression run exposed one over-broad runtime change in sub-composition host visibility and one CI-only baseline trap.
Closes#590, #589, #588, #587, #586, and #584.
## What this fixes
### CLI/runtime edge cases
- Makes the GSAP infinite-repeat lint rule ignore JavaScript comments, so literal `repeat:-1` text in comments is not flagged.
- Lets the compositions CLI inspect `<template>` content, count visual-only template descendants, estimate simple GSAP durations, and suppress root `data-start` warnings in sub-composition lint mode.
- Preserves runtime bootstrap scripts when body scripts are coalesced, and injects the runtime into a real `<head>` when source HTML has no head.
- Keeps #589 fixed by loading and rendering template-wrapped sub-composition content, while restoring host visibility to the shorter of the authored parent clip window and the child composition live timeline.
- Resolves snapshot/validate viewport size from root `data-width` / `data-height` instead of falling back to 1920x1080.
- Skips fully off-frame text boxes during contrast sampling and bounds-checks ring samples so contrast output no longer emits `null:1` / `NaN:1`.
- Marks muted videos as `data-has-audio="false"` in the core timing compiler, which fixes the same-src muted `<video>` + separate `<audio>` StaticGuard case.
- Keeps user-authored `hf-seek` listeners reachable during capture by preventing author scripts from being merged into the runtime bootstrap path.
### Shared helper cleanup
- Removes the stale producer-local timing compiler duplicate; producer compilation now consumes the core timing compiler.
- Centralizes HTML document helpers in core: fragment parsing, embedded runtime stripping, head/body script injection, and early-head injection.
- Centralizes the CLI layout/snapshot static HTML server.
- Adds browser-safe core subpath helpers for Lottie readiness and CLI screenshot clip calculation; Studio's Vite config keeps the screenshot clip helper self-contained so clean-checkout test startup does not value-import core `.ts` source.
- Replaces the engine parity-contract copy with a core re-export.
- De-duplicates render-job cleanup and Studio static file-serving callbacks.
### Regression hardening
- Replaces the embedded-runtime script stripping regex with a script-tag scanner that handles closing tags like `</script >`.
- Escapes inline script bodies before wrapping them in `<script>` tags, so authored `</script` and `<!--` text cannot break out of the injected wrapper script.
- Shares media-duration clamping between core and producer, with a 50 ms tolerance for ffprobe precision drift between local and CI media stacks.
- Pins the affected style fixture SFX durations in source so style-1 and style-9 compile deterministically.
- Restores the `vfr-screen-recording` video golden to the CI-stable baseline; the current CI failure showed the Linux render matches the old golden, while the locally refreshed macOS golden was the mismatch.
## Root cause
The CLI paths had accumulated assumptions that held for simple direct-root landscape compositions but not for current composition patterns: DOM queries did not enter template content, snapshot/validate used a fixed viewport, runtime and author scripts shared a coalescing bucket, and timing compilation treated every video as audio-bearing unless authors manually overrode it.
The style shard failures were not product regressions. Local and CI media probing disagreed on the short SFX clip duration by about 45 ms, and the compiler was clamping authored durations to the locally probed value. The shared clamp tolerance preserves explicit author/source durations for small probe precision differences while still clamping real overflows.
The vfr fast-shard failure was a bad baseline refresh: CI actual frames matched the old `vfr-screen-recording` baseline at 40+ dB PSNR, but mismatched the macOS-refreshed golden at ~18-22 dB. The fix is to keep the Docker/Linux-stable video golden and only retain the deterministic compiled snapshot change.
The sub-composition regression came from treating a host's authored parent window as the only visibility boundary. That made settled child overlays stay visible after their own live GSAP timeline ended. The corrected runtime behavior respects both contracts: parent clips still bound where the host can appear, and the child live timeline can end the host earlier.
## Verification
### Local checks
- `bunx oxfmt --check packages/core/src/runtime/init.ts packages/core/src/runtime/init.test.ts`
- `bunx oxlint packages/core/src/runtime/init.ts packages/core/src/runtime/init.test.ts`
- `bun run --cwd packages/core test src/runtime/init.test.ts`
- `bun run --cwd packages/cli test src/commands/compositions.test.ts src/utils/compositionViewport.test.ts`
- `bun run build:hyperframes-runtime`
- `bun run --cwd packages/producer test --keep-temp --sequential style-12-prod style-5-prod`
- `bun run --cwd packages/producer test --sequential vfr-screen-recording hdr-hlg-regression style-7-prod`
- `bun run --cwd packages/core test src/compiler/htmlCompiler.test.ts src/compiler/timingCompiler.test.ts src/index.test.ts`
- `bunx oxfmt --check packages/core/src/compiler/timingCompiler.ts packages/core/src/compiler/htmlCompiler.ts packages/core/src/compiler/htmlCompiler.test.ts packages/core/src/compiler/index.ts packages/core/src/index.ts packages/core/src/index.test.ts packages/producer/src/services/htmlCompiler.ts`
- `bunx oxlint packages/core/src/compiler/timingCompiler.ts packages/core/src/compiler/htmlCompiler.ts packages/core/src/compiler/htmlCompiler.test.ts packages/core/src/compiler/index.ts packages/core/src/index.ts packages/core/src/index.test.ts packages/producer/src/services/htmlCompiler.ts`
- `bun run --cwd packages/core typecheck`
- `bun run --cwd packages/producer typecheck`
- `bun run --cwd packages/producer test --sequential style-1-prod style-9-prod`
- `bun run --filter @hyperframes/studio test` with `packages/core/dist` temporarily hidden to simulate clean-checkout config loading
- `git diff --check`
### CI artifact checks
- Inspected failed run `25225854394` job `73969147096`: style-1 failed only on `click-sfx` `1.044898` vs `1` duration/end.
- Inspected failed run `25225854394` job `73969147061`: style-9 failed only on SFX `1.044898`-based duration/end mismatches.
- Inspected failed run `25225854394` job `73969147048`: `vfr-screen-recording` compilation/audio passed, visual failed after comparing against the macOS-refreshed golden.
- Compared the first 10 uploaded CI vfr failure frames against the restored old baseline; minimum PSNR was `40.444705`, above the fixture threshold of `28`.
### Repro checks
- `bun packages/cli/src/cli.ts lint /tmp/hf-590-repro` now passes without `gsap_infinite_repeat`.
- `bun packages/cli/src/cli.ts snapshot /tmp/hf-587-repro --at 0.5 --timeout 1000` now writes a 1080x1920 PNG.
- `bun packages/cli/src/cli.ts validate /tmp/hf-588-repro --timeout 500` no longer emits `null:1` / `NaN:1` contrast output.
- `bun packages/cli/src/cli.ts validate /tmp/hf-586-repro --timeout 500 --contrast false` no longer emits the muted-video StaticGuard contract error.
- `bun packages/cli/src/cli.ts compositions /tmp/hf-589-gsap-repro` now reports `foo 0.5s 1920x1080 1 element`.
- `bun packages/cli/src/cli.ts snapshot /tmp/hf-589-gsap-repro --at 0.25 --timeout 2000` captures the expected template-backed red frame.
- `bun packages/cli/src/cli.ts snapshot /tmp/hf-584-repro --at 0.5,1.5 --timeout 500` captures the expected post-seek green frame.
### Browser verification
- Refreshed the local side-by-side comparison page at `qa-artifacts/pr-591-video-compare/index.html`.
- Served the comparison page locally and used `agent-browser` to load `style-12-prod`, play both videos quickly to the failed window, pause, and inspect the side-by-side frame.
- Browser proof screenshot: `qa-artifacts/pr-591-video-compare/browser-proof/fixed-style12-labeled.png`.
- Browser proof recording: `qa-artifacts/pr-591-video-compare/browser-proof/fixed-style12.webm`.
- Earlier Studio proof artifacts remain local-only: `qa-artifacts/dedupe-refactor-preview.png`, `qa-artifacts/dedupe-refactor-preview-after-play.png`, `qa-artifacts/dedupe-refactor-preview.webm`.
## Notes
- Browser proof and CI diagnostic artifacts are intentionally local-only and not committed.
- Studio's Vite config intentionally keeps the thumbnail clip helper inline because Vite/Vitest config startup runs through Node's loader before package source `.ts` imports are transformed.
- The committed PR diff changes `vfr-screen-recording/output/compiled.html` but no longer changes `vfr-screen-recording/output/output.mp4` relative to `main`.
- I attempted a local `linux/amd64` Docker validation to mirror CI, but the local Docker build was blocked by Debian package download failures. The arm64 Docker image also cannot launch the x64 Puppeteer headless shell under OrbStack. The vfr baseline decision is therefore based on the uploaded CI artifact comparison above.
- I kept this validated issue batch in one PR because the fixes overlap the same CLI/runtime capture surfaces.
## Problem
Studio timeline editing still had two rough edges that made the latest alpha feel less polished when testing it like a video editor would:
- Timeline clips for anonymous DOM nodes could surface internal fallback identities like `__node__index_*`, which made the timeline look broken instead of authored.
- Elements without a stable `id` could still appear in the timeline and canvas editor, but authors did not get direct lint guidance that those elements are weaker targets for Studio and agent edits.
## What this fixes
- Adds a non-blocking `studio_missing_editable_id` lint warning for timeline-visible elements that do not have an `id`.
- Makes the warning point to the exact element and recommend stable, human-readable ids such as `hero-title` or `scene-1-card`.
- Stops using synthetic node-index ids as runtime clip identity for anonymous DOM nodes.
- Gives anonymous clips readable labels from authored metadata, composition ids, DOM ids, class names, asset filenames, text content, or a simple ordinal fallback.
- Keeps those labels display-only in Studio and uses key-first identity for matching, dragging, resizing, and manifest merge preservation.
- Covers the duplicate-label case where two anonymous clips both render as `Card` but still stay separate timeline entries.
## Root cause
The runtime manifest used synthetic node-index ids as both identity and display fallback for timeline nodes that had no stable author-provided id. Studio then treated those internal values as user-facing clip names.
The first pass improved the display label, but it also risked using that friendly label as internal identity. Two anonymous clips with the same label could then collapse into the same logical timeline element. The fix separates display labels from internal identity and prefers the timeline key whenever Studio needs to match an element.
The linter also had correctness checks for render and runtime behavior, but it did not teach authors when a timeline-visible element would be harder for Studio and agents to patch reliably. That left missing ids as a silent authoring quality issue instead of actionable guidance.
## Verification
### Local checks
- `bun run --cwd packages/core test -- src/lint/rules/core.test.ts src/runtime/timeline.test.ts` -> 41 tests pass
- `bun run --cwd packages/studio test -- src/player/hooks/useTimelinePlayer.test.ts src/player/components/timelineTheme.test.ts` -> 23 tests pass
- `bun run --cwd packages/core typecheck`
- `bun run --cwd packages/studio typecheck`
- `bun run --cwd packages/studio build` -> passes with the existing Vite chunk-size warning
- `bunx oxlint $(git diff --name-only origin/main...HEAD)` -> 0 warnings, 0 errors
- `bunx oxfmt --check $(git diff --name-only origin/main...HEAD)`
- `git diff --check origin/main...HEAD`
### Browser verification
- Created a scratch project at `/tmp/hf-pr533-conflict-verify` with two timed anonymous `.card` clips that both label as `Card`.
- Started the local Studio dev server for `pr-533-conflict-verify`.
- Used `agent-browser` to verify the timeline renders two separate `Card` clips instead of collapsing duplicate anonymous labels.
- Used `agent-browser` to open the Studio lint modal and verify it shows human-readable missing-id warnings, not internal node-index labels.
- Used `agent-browser` to click Play after the lint pass and confirm the timeline remains usable.
- Recorded the tested Studio flow with `agent-browser`.
## Notes
- Rebased onto current `main`; conflict resolution preserved both the newer mainline Studio shortcut/lint behavior and this PR's anonymous-clip identity split.
- GitHub Actions are running on the rebased head.
- Scratch verification files are intentionally not committed.
- Local screenshots and recording from this rebase pass are under `.codex-artifacts/pr-533-conflict-rebase-2026-04-29/`.
## Problem
The Catalog did not include the four prompt-matched Stronkter one-shot HyperFrames projects, and registry metadata only supported a plain author string, so there was no structured way to show creator attribution or the original generation prompt on generated catalog pages.
## What this fixes
- Adds four Catalog blocks matching the provided prompts, in order:
- `north-korea-locked-down`
- `apple-money-count`
- `nyc-paris-flight`
- `goonvpn-youtube-spot`
- Attributes each block to [Stronkter](https://x.com/Stronkter).
- Stores and renders the original source prompt for each generated catalog page.
- Adds a local realistic map plate for the North Korea block so rendering does not depend on live map tile requests.
- Extends registry item metadata/schema with `authorUrl` and `sourcePrompt`.
- Updates catalog page generation to read items from `registry/registry.json`, keeping generated docs aligned to the public registry manifest.
- Ignores normal browser media preload `net::ERR_ABORTED` request failures for media assets during `hyperframes validate`, while preserving failures for real missing assets.
## Root cause
The imported projects are Catalog-ready compositions, but the registry/docs pipeline did not have first-class source-prompt or linked-author fields to expose creator credit on generated MDX pages. The audio-backed compositions also surfaced a validation edge case: Chrome can report aborted media preload requests as `net::ERR_ABORTED` even when the audio file exists and playback is valid.
## Verification
### Local
- `bun run --filter @hyperframes/cli test src/commands/validate.test.ts`
- `bun run --filter @hyperframes/core test src/registry/types.test.ts`
- `bun run sync-schemas:check`
- `bunx oxlint packages/cli/src/commands/validate.ts packages/cli/src/commands/validate.test.ts packages/core/src/registry/types.ts packages/core/src/registry/types.test.ts scripts/generate-catalog-pages.ts`
- `bunx oxfmt --check ...` on changed source, registry, docs, and composition files
- `git diff --check`
- `bun packages/cli/src/cli.ts lint` and `validate` against temp installed projects for all four blocks
- Lefthook pre-commit: lint/format/typecheck on the initial commit, plus format on the amend
- Lefthook commit-msg: commitlint
### Browser
- Exercised all four blocks through HyperFrames preview routes with `agent-browser`.
- Captured playback screenshots and WebM recordings for:
- `north-korea-locked-down`
- `apple-money-count`
- `nyc-paris-flight`
- `goonvpn-youtube-spot`
## Notes
- The zip also contained unrelated project directories, but this PR intentionally includes only the four prompt-matched Catalog blocks requested here.
- The imported one-shot compositions may trigger the existing large-composition lint warning, but there are no lint errors and runtime validation passes.
## Problem
Closes#555. Studio users could inspect the preview, but there was no first-class way to capture the current rendered frame as an image.
## What this fixes
- Adds a `Capture` action to the Studio header toolbar so it does not cover the video preview.
- Downloads the current composition frame as a PNG using the current player time.
- Extends the existing thumbnail route and Studio/CLI thumbnail generators with an explicit PNG format path while preserving JPEG thumbnails for existing previews.
- Adds URL/filename utility coverage plus thumbnail route coverage for PNG requests.
## Root cause
Studio already had frame thumbnail generation, but the API path was JPEG-oriented and the editor UI only used it for previews. There was no current-frame capture affordance wired to the player state.
## Verification
### Local
- `bun run --filter @hyperframes/core test src/studio-api/routes/thumbnail.test.ts`
- `bun run --filter @hyperframes/studio test src/utils/frameCapture.test.ts src/player/components/PlayerControls.test.ts`
- `bun run --filter @hyperframes/studio typecheck`
- `bun run --filter @hyperframes/core typecheck`
- `bun run --filter @hyperframes/cli typecheck`
- `bunx oxlint packages/cli/src/server/studioServer.ts packages/core/src/studio-api/routes/thumbnail.test.ts packages/core/src/studio-api/routes/thumbnail.ts packages/core/src/studio-api/types.ts packages/studio/src/App.tsx packages/studio/src/icons/SystemIcons.tsx packages/studio/vite.config.ts packages/studio/src/utils/frameCapture.ts packages/studio/src/utils/frameCapture.test.ts`
- `bunx oxfmt --check packages/cli/src/server/studioServer.ts packages/core/src/studio-api/routes/thumbnail.test.ts packages/core/src/studio-api/routes/thumbnail.ts packages/core/src/studio-api/types.ts packages/studio/src/App.tsx packages/studio/src/icons/SystemIcons.tsx packages/studio/vite.config.ts packages/studio/src/utils/frameCapture.ts packages/studio/src/utils/frameCapture.test.ts`
- `git diff --check`
### Browser
<img width="1027" height="910" alt="image" src="https://github.com/user-attachments/assets/71973af4-0279-4074-9
<img width="1026" height="902" alt="Screenshot 2026-04-29 at 16 17 22" src="https://github.com/user-attachments/assets/a32e1c19-b793-40b9-82f8-de8bbb11f123" />
060-130839a2d419" />
* fix(lint): remove root_composition_missing_data_duration
Lint cannot statically observe the runtime's true Infinity-emission
condition: it requires a finite GSAP timeline duration AND a finite
media/sub-comp window AND timeline > floor + 1, none of which are
visible to the static linter. The looping shapes that drive the
condition are already covered by `gsap_infinite_repeat` and
`gsap_repeat_ceil_overshoot` (both from #243), which point at the
real authoring mistake — flagging the missing duration separately
was a noisy proxy for the same signal.
Per #490 review discussion, deprecate the static rule and let those
two GSAP rules carry the pre-render coverage. If perfect precision
on `durationInFrames = Infinity` is needed, that belongs on the
runtime/render path where `shouldEmitNonDeterministicInf` is
actually known.
Add regression tests pinning the removal: a docs-compliant root
without `data-duration` no longer warns, and the canonical
loop-inflated shape now surfaces only via `gsap_infinite_repeat`
instead of two duplicate findings.
* docs(skills): update step-6 build checklist after rule removal
Drops the `root_composition_missing_data_duration` reference now that
the rule is gone. Keeps the authoring recommendation (and explains the
runtime Infinity case) but points authors at the GSAP rules that
actually carry the lint signal: `gsap_infinite_repeat` and
`gsap_repeat_ceil_overshoot`.
## Summary
- preserve alpha for render-injected video frames by detecting alpha streams with ffprobe and extracting alpha video frames as PNG
- keep `<video loop>` semantics through static parsing, compiler duration resolution, browser media discovery, and render frame lookup
- fail embedded preview startup before opening a broken browser page when the Studio bundle is missing
- align snapshot frame injection with looped media timing and VP9 alpha extraction
## Why
The Studio preview and rendered MP4 could disagree for timed transparent looped videos. The Comfy funding composition exposed two separate parity bugs: render-injected frames needed alpha-preserving PNG extraction, and the compiler was clamping a looped `data-duration="4"` video down to the 3.125s source duration. After the first source cycle, render lookup treated the video as inactive, hid the native video, and produced the blank polygon/glow the user saw around the rounded `0:03` mark.
`hyperframes lint` and `hyperframes validate` did not catch this because they check syntax/load/console/accessibility, not preview-vs-render visual parity. This PR adds regression coverage for the compiler loop-duration path and frame lookup path.
## Verification
- `bun run --filter @hyperframes/core test -- src/compiler/timingCompiler.test.ts src/compiler/htmlCompiler.test.ts`
- `bun test packages/producer/src/services/htmlCompiler.test.ts`
- `bun run --filter @hyperframes/engine test -- videoFrameExtractor ffprobe`
- `bun run --filter @hyperframes/core typecheck`
- `bun run --filter @hyperframes/engine typecheck`
- `bun run --filter @hyperframes/producer typecheck`
- `bun run --filter @hyperframes/cli typecheck`
- `bun run lint`
- `bun run format:check ...` on touched files
- Comfy project: `node packages/cli/dist/cli.js validate` -> no console errors, 44 text elements pass WCAG AA
- Comfy project patched render from source: `/tmp/comfy-render-compare/fixed6-comfy.mp4`, 1920x1080, 30fps, 21.8s, 654 frames
- 3.00s-3.97s render contact sheet: `/tmp/comfy-render-compare/fixed6-window-contact.png`
- targeted fixed render capture at 3.733s: `/tmp/comfy-render-compare/probe-capture-fixed/captured/frame_000112.jpg`
- agent-browser Studio proof screenshot at 3.7s: `/tmp/comfy-render-compare/agent-browser-studio-3_7-fixed.png`
- agent-browser-driven recording of 3s seek pass: `/tmp/comfy-render-compare/agent-browser-wysiwyg-3s-fixed.webm`
Note: `bun run --filter @hyperframes/cli dev -- validate` is blocked in source mode by the existing `contrast-audit.browser.js` default-export loader issue; packaged `node packages/cli/dist/cli.js validate` passes for this project.
## Problem
Studio seek could still wake nested composition media even when the transport itself stayed paused.
In the real repro from `apple-presentation`, scrubbing to `0:29` without pressing play lands on the `slide-translation` composition. That composition contains `Multilingual_Journey.mp4` inside the composition host. On the broken path:
- the main Studio transport remained paused
- the nested video advanced and stayed playing anyway
- the user saw autoplay-like behavior even though the only action was a seek
That was especially confusing because the seek was otherwise correct: the timeline moved to the right point, but the nested media stopped obeying the paused transport state.
## What this fixes
### Nested media now participates in runtime media sync
- the runtime media cache no longer assumes only `video[data-start]` / `audio[data-start]` are relevant
- nested media inside a composition host can now be included in the same timed-media sync pass even when the inner media element does not carry its own authored `data-start`
### Nested media timing is resolved in the host composition window
- nested media start time is resolved against the enclosing composition host instead of falling back to scene-local `0`
- nested media duration is clamped to the enclosing composition window so it stays aligned with the authored host clip timing
### Paused seeks land on the right frame and stay paused
- after seeking into a nested composition, the inner media is now seeked to the correct frame relative to the host timeline
- because it is now part of the managed media set, the runtime also keeps it paused when the transport is paused instead of letting it continue playing on its own
### Regression coverage
- adds a runtime regression test that covers a nested composition video with no local `data-start`
- the test verifies that `player.seek(29)` leaves the nested video paused while landing it at the expected `currentTime`
## Root cause
The bug came from a mismatch between deterministic timeline seeking and media ownership.
### 1. The runtime only managed media with direct timing attrs
`refreshRuntimeMediaCache()` only collected `video[data-start]` and `audio[data-start]`. That works for root-level timed media, but not for media embedded inside a composition host where timing is inherited from the host composition rather than duplicated onto the inner media node.
### 2. Nested composition seek could still advance inner media
The runtime intentionally rearms sibling timelines during deterministic seek so nested timelines land on the right local offsets. That part is necessary and correct.
But because the nested video was not part of the managed media cache, it could advance during that seek path without being brought back under the paused transport state afterward.
### 3. The runtime had no way to reconcile the two
So the system had an inconsistent split:
- timeline seek knew about the nested composition timeline
- media sync did not know about the nested media inside it
The fix closes that split by resolving nested media start/duration from the enclosing composition context and running it through the same sync logic as other managed media.
## Verification
### Local checks
- `bun run --filter @hyperframes/core typecheck`
- `bun run test -- src/runtime/init.test.ts src/runtime/media.test.ts src/runtime/player.test.ts` in `packages/core`
- `bunx oxlint packages/core/src/runtime/media.ts packages/core/src/runtime/init.ts packages/core/src/runtime/init.test.ts`
- `bunx oxfmt --check packages/core/src/runtime/media.ts packages/core/src/runtime/init.ts packages/core/src/runtime/init.test.ts`
### Browser verification
Verified against a repo-backed local Studio preview of `apple-presentation`:
- opened `http://127.0.0.1:3014/#project/apple-presentation`
- seeked to `0:29` without pressing play
- confirmed the visible composition switched to `slide-translation`
- confirmed `Multilingual_Journey.mp4` landed at a non-zero `currentTime` (`3.067` in the verified run)
- confirmed the nested video stayed `paused` and its `currentTime` remained stable across a follow-up check instead of autoplaying
## Notes
- the local browser proof artifacts under `qa-artifacts/autoplay-seek/` are verification-only and are not part of this PR
- this PR is intentionally scoped to nested media ownership during paused seek; it does not broaden into unrelated runtime media refactors beyond bringing inherited nested media under the existing sync contract
Fixes#473.
## Problem
The HyperFrames skill now tells agents to add deterministic `tl.set()` hard-kills after elements fade out at beat / scene boundaries, but the linter did not enforce that rule outside the narrow caption-specific check.
That made the rule easy for sub-agents to ignore: an element could fade to `opacity: 0` exactly as the next clip starts, with no explicit hidden-state set at the boundary. During non-linear seeking or frame capture, that leaves the final visibility state dependent on tween interpolation instead of an authored deterministic kill.
## What this fixes
This PR adds a generalized GSAP lint warning for scene-boundary exits:
- detects GSAP `to` / `fromTo` exit tweens that end at or near a clip `data-start` boundary
- treats `opacity: 0`, `autoAlpha: 0`, `visibility: "hidden"`, and `display: "none"` as hidden exit states
- requires a matching same-selector `tl.set(...)` hidden state at the same boundary
- scopes clip-boundary matching to the timeline's registered composition so sub-composition exits do not match unrelated root boundaries
- reports `gsap_exit_missing_hard_kill` with the selector, boundary time, source snippet, and a fix hint that preserves the authored hidden property when possible
- keeps valid compositions quiet when the boundary hard-kill already exists
## Why
Clip boundaries are the exact points where rendered frames are most sensitive to stale DOM state. A fade-out tween describes a transition, but it does not give the linter or the authoring model an explicit deterministic state to land on when seeking around the boundary.
The existing caption rule proved the class of bug was worth catching, but it only applied to caption-loop patterns. The issue in #473 is broader: any element inside a timed composition can exit at a scene boundary and need the same deterministic cleanup.
## Root cause
The GSAP lint rule parser already calculated tween windows and clip metadata existed in the lint context, but no rule connected those two facts:
- clip `data-start` values were not used as scene-boundary checkpoints for GSAP exits
- parsed GSAP windows tracked property names, but not enough property values to tell whether a tween ended in a hidden state
- hard-kill detection only existed as a caption-specific regex, so normal scene elements were missed
This PR extends the existing GSAP window metadata with parsed property values, then checks hidden-state exits against same-composition clip start boundaries and same-selector `tl.set` calls.
## Verification
### Local checks
- `bun run --filter @hyperframes/core test src/lint/rules/gsap.test.ts`
- `bunx oxlint packages/core/src/lint/rules/gsap.ts packages/core/src/lint/rules/gsap.test.ts`
- `bunx oxfmt --check packages/core/src/lint/rules/gsap.ts packages/core/src/lint/rules/gsap.test.ts`
- `bun run --filter @hyperframes/core typecheck`
- `bun run --filter @hyperframes/core test`
- `bun run --filter @hyperframes/core build`
### CLI verification
Verified against local fixtures where `#headline` exits at the next clip boundary without a hard kill:
- opacity fixture reports `gsap_exit_missing_hard_kill` for `#headline` at `3.00s`
- autoAlpha fixture reports the same warning and suggests `tl.set("#headline", { autoAlpha: 0 }, 3.00)`
- sub-composition regression test confirms a `sub` timeline exit no longer matches an unrelated root composition boundary
### Browser verification
Verified the Studio lint flow with `agent-browser` against the autoAlpha fixture:
- opened Studio at `http://127.0.0.1:43174/#project/issue-473-autoalpha`
- clicked the real `Lint` button
- confirmed the lint modal shows the new warning and the property-preserving `{ autoAlpha: 0 }` fix hint
- saved local proof artifacts under `qa-artifacts/issue-473/`
## Notes
- the `tmp/issue-473-*` fixtures and `qa-artifacts/issue-473` browser proof are local-only and are not part of this PR
- this intentionally stays heuristic-based: it warns near clip start boundaries instead of trying to build a full GSAP execution model
- expression-valued GSAP props and deeper regex-parser limitations remain outside this PR's scope; those are parser-hardening work, not required for the bug in #473
Miguel Ángel