## Problem
HyperFrames Studio made frame-accurate playback review slower than expected for editor-style workflows. Issue #527 called out missing loop playback, frame display/jump controls, preview-focused Space handling, frame stepping, and NLE-style J/K/L shuttle controls.
## What this fixes
- Adds a persistent Studio loop toggle and makes the playback loop restart when enabled.
- Adds a time/frame display toggle plus a jump-to-frame input in the player controls.
- Adds frame math helpers and frame-step behavior at the Studio preview frame rate.
- Expands keyboard handling so preview-focused Space toggles playback, ArrowLeft/ArrowRight step frames, Shift+Arrow steps 10 frames, and J/K/L shuttle controls work from the preview/timeline surface while ignoring form/button/slider targets.
- Adds J/K/L shuttle behavior: J plays backward, K pauses, L plays forward, repeated J/L ramps 1x -> 2x -> 4x, and K-held J/L frame-steps.
- Makes the preview wrapper focusable so keyboard playback shortcuts work after focusing the preview area.
## Root cause
The Studio playback layer only exposed mouse scrubbing, basic play/pause, a seconds-based readout, and slider-local arrow-key nudges. The global Space shortcut was also gated to `document.body`, so it stopped working once the actual preview/editor surface had focus. Studio needed a single playback-control layer above the runtime adapter that could translate editor keyboard intent into deterministic seek/play/pause operations.
## Verification
### Local checks
- `bun install`
- `bun run --filter @hyperframes/core build:hyperframes-runtime`
- `bunx oxfmt --check packages/studio/src/player/lib/time.ts packages/studio/src/player/lib/time.test.ts packages/studio/src/player/store/playerStore.ts packages/studio/src/player/store/playerStore.test.ts packages/studio/src/player/hooks/useTimelinePlayer.ts packages/studio/src/player/components/PlayerControls.tsx packages/studio/src/player/components/PlayerControls.test.ts packages/studio/src/components/nle/NLEPreview.tsx`
- `bunx oxlint packages/studio/src/player/lib/time.ts packages/studio/src/player/lib/time.test.ts packages/studio/src/player/store/playerStore.ts packages/studio/src/player/store/playerStore.test.ts packages/studio/src/player/hooks/useTimelinePlayer.ts packages/studio/src/player/components/PlayerControls.tsx packages/studio/src/player/components/PlayerControls.test.ts packages/studio/src/components/nle/NLEPreview.tsx`
- `bun run --filter @hyperframes/studio test -- src/player/lib/time.test.ts src/player/store/playerStore.test.ts src/player/components/PlayerControls.test.ts src/player/hooks/useTimelinePlayer.test.ts` -> 4 files passed, 52 tests passed
- `bun run --filter @hyperframes/studio typecheck`
- `bun run --filter @hyperframes/studio build`
- `git diff --check`
- Lefthook during commit -> lint, format, typecheck, commitlint pass
### Browser verification
- Created a temp project at `/tmp/hf-studio-nle-controls` with an animated 10s GSAP timeline.
- Started local Studio preview via `bun run --filter @hyperframes/cli dev -- preview /tmp/hf-studio-nle-controls` at `http://localhost:5194`.
- Used `agent-browser` to verify:
- loop toggle changes to active state
- frame display shows `current / total` frames
- jump-to-frame input moves the seek position to frame 45 / frame 150
- focused preview accepts Space play/pause
- ArrowRight advances one frame from preview focus
- J plays backward from frame 150 to a lower frame, then K stops
- agent-browser-driven recording of the tested flow completed
## Notes
- Local proof artifacts are intentionally not committed:
- `qa-artifacts/studio-nle-controls/frame-controls.png`
- `qa-artifacts/studio-nle-controls/playback-controls.webm`
- Closes#527.
The studio shell paints a #0a0a0a body but never declares `color-scheme`,
so browsers render native UA chrome (scrollbars, form controls, focus
rings) in the light palette and the mismatch is obvious — especially
scrollbars, which appear as light tracks sitting on top of a near-black
panel.
Studio doesn't expose a theme toggle; the UI is dark-only. Declaring
`color-scheme: dark` on `:root` lines up the browser-native surfaces
with the rest of the chrome.
* fix(studio): restore flex layout inside the NLE timeline panel
Without `flex flex-col`, the toolbar and Timeline children render as
block elements and Timeline's `h-full` takes the panel's entire height.
The toolbar still occupies its own ~45px of flow, pushing the scroll
area below the viewport and clipping the scrollbar at the bottom of the
right-side panel.
* fix(studio): pin toolbar height with flex-shrink-0 and trim comment
Wrap the toolbar slot in a flex-shrink-0 div so Timeline back-pressure
can't squeeze the toolbar below its natural height. The visible bug
doesn't manifest at current sizes, but in a flex-col container both
children are flex items and the toolbar has no shrink guard of its own.
Trim the inline comment to a single line — the rationale belongs in
the commit message, not at the call site.
## Problem
Studio still broke down in three concrete authoring flows around timeline assets:
- you could import media into Assets, but not drag an already-imported asset from the Assets tab onto the timeline and persist it into source
- dragging a file from outside the app onto the timeline only uploaded it into Assets instead of placing it at the dropped time/track
- once a clip was on the timeline, there was no reliable keyboard delete flow for removing it safely from source
While implementing direct external drops, another real bug showed up:
- valid binary uploads like `raycast.mp4` from `Downloads` were being rejected as unsupported media in Studio dev because the Vite API bridge was corrupting multipart request bodies before they reached the upload route
## What this fixes
### Timeline asset placement from inside Studio
- asset cards in the Assets tab are draggable
- the timeline accepts asset drops even when it already has clips
- dropping an asset onto the timeline inserts a new clip into the active composition source at the dropped time / track
- asset paths are rewritten relative to the target composition file so drops into sub-compositions resolve correctly
- the new clip is persisted immediately and the preview refreshes
### Direct external file drops onto the timeline
- dropping a file from outside the app onto the timeline now uploads it and places it onto the dropped track/time in one shot
- it no longer stops halfway by only adding the file into Assets
- multiple dropped files are placed using the same drop start and successive tracks
### Delete key support
- selected timeline clips can now be deleted with `Delete` / `Backspace`
- deletion is persisted back to source, not just removed from local state
- the delete path now uses a server-side DOM mutation helper with LinkeDOM for structural safety instead of client-side string surgery
### Binary upload fix for media files
- the Studio Vite API bridge now forwards non-GET request bodies as raw bytes instead of decoding them as UTF-8 text
- that preserves multipart uploads for binary media like MP4s
- valid local videos from `Downloads` no longer get rejected as `Unsupported media skipped` just because the dev bridge corrupted the request body
- upload validation now probes buffered media through a temp file path that preserves the file extension before saving into the project
## Root cause
There were really two separate gaps:
### 1. Asset placement / deletion workflow gaps
The timeline and asset systems already existed, but they were disconnected:
- `AssetsTab` only supported copy/import flows
- `Timeline` only handled raw file import, not positioned placement for existing assets
- there was no utility layer for converting a dropped asset into persisted timeline HTML
- there was no structurally safe deletion path for arbitrary selected timeline clips
### 2. Binary upload corruption in Studio dev
The Studio Vite API bridge rebuilt non-GET request bodies like this:
- read each request chunk
- call `chunk.toString()`
- concatenate into a string
- construct the Fetch `Request` from that string body
That works for text, but it corrupts multipart binary uploads. By the time the upload route wrote the received file and ran `ffprobe`, otherwise valid MP4s had already been mangled in-flight.
## Behavior
- dropping on `index.html` inserts the asset into the root composition
- dropping while drilled into a composition inserts into that composition file instead
- drop X position maps to `data-start`
- drop Y position maps to the current visible track row, with a new bottom track created if the drop lands below existing rows
- images default to a short finite duration
- audio/video default to their metadata duration when available, with a fallback duration if metadata cannot be read quickly
- pressing `Delete` on a selected clip removes that clip from the underlying HTML source and clears selection in Studio
- valid uploaded MP4s now survive the Studio dev API bridge intact instead of being rejected during upload validation
## Verification
### Local checks
- `bunx oxlint packages/core/src/studio-api/helpers/sourceMutation.ts packages/core/src/studio-api/helpers/sourceMutation.test.ts packages/core/src/studio-api/helpers/mediaValidation.ts packages/core/src/studio-api/helpers/mediaValidation.test.ts packages/core/src/studio-api/routes/files.ts packages/studio/src/App.tsx packages/studio/src/components/nle/NLELayout.tsx packages/studio/src/components/sidebar/AssetsTab.tsx packages/studio/src/player/components/Timeline.tsx packages/studio/src/player/components/Timeline.test.ts packages/studio/src/utils/timelineAssetDrop.ts packages/studio/src/utils/timelineAssetDrop.test.ts packages/studio/vite.config.ts packages/studio/vite.request-body.ts packages/studio/vite.request-body.test.ts`
- `bunx oxfmt --check` on the touched files
- `bun run --filter @hyperframes/core typecheck`
- `bun run --filter @hyperframes/studio typecheck`
- `bun test packages/core/src/studio-api/helpers/sourceMutation.test.ts packages/core/src/studio-api/helpers/mediaValidation.test.ts packages/studio/src/player/components/Timeline.test.ts packages/studio/src/utils/timelineAssetDrop.test.ts packages/studio/vite.request-body.test.ts`
### Browser / live verification
Verified against a live local Studio fixture:
- dragging an existing asset from the Assets tab onto the timeline creates a persisted clip at the dropped position
- dropping a file from outside the app directly onto the timeline uploads it and creates a persisted clip at the dropped position
- selecting a dropped clip and pressing `Delete` removes it from both the live timeline and the saved source HTML
- valid MP4 uploads like `raycast.mp4` now succeed through the live Studio upload route instead of being rejected as unsupported media
## Notes
- the local `timeline-trio-verify` and `timeline-overlap-debug` projects used for verification are local-only and are not part of this PR
- this PR is about asset placement, upload correctness, and deletion safety; it does not broaden into richer editing workflows beyond placing/removing clips from the timeline
Guard buildHyperframesRuntimeScript() against missing entry.ts so it
returns null instead of crashing with esbuild stderr output. Add
getHyperframeRuntimeScript() that returns the pre-built IIFE as a
baked-in string constant — no esbuild, no file I/O, no import.meta.url.
Consolidate CLI runtime source resolution into a single module with
a clear priority chain: esbuild from source (dev) → inlined constant
(production) → pre-built artifact file (fallback).
Add CI smoke test that npm-packs the CLI, installs globally, runs
hyperframes preview, and asserts no stderr errors + runtime endpoint
returns JS.
Bump version to 0.4.16.
## Summary
- preserve authored non-root composition timing before runtime sanitization so Studio can build the correct master timeline for chained subcompositions
- prefer the fresh runtime source in Studio dev so local preview does not serve a stale `/api/runtime.js`
- restrict preserved authored timing inference to the Studio timeline payload instead of the general runtime resolver
## What this fixes
This PR fixes the Apple presentation class of failures where the root `index.html` / `Master` view looked correct at first and then collapsed into an incorrect short timeline.
Before this change:
- the master transport could report a short duration like `0:12` instead of the real deck length (`2:21` in the Apple project)
- composition clips bunched near the start instead of laying out sequentially across the deck
- seeking into later parts of the deck would land in the wrong place or show the wrong active composition
- local Studio debugging could be misleading because dev sometimes served a stale runtime bundle
After this change:
- the master transport reflects the authored composition-chain duration
- master clips resolve linearly across the whole deck
- late seeks land on the correct slide window
- Studio dev uses the current runtime implementation, so local preview matches the branch you are testing
## Root cause
There were two related issues:
1. Studio/master timeline inference lost authored composition timing
- missing timing attrs were treated like `0` instead of `null`
- non-root composition `data-duration` / `data-end` were stripped before Studio timing resolution could use them
- root duration inference trusted an incomplete live timeline window instead of the authored composition chain
2. Preserved authored timing leaked into the general runtime resolver
- preserving authored timing was correct for Studio timeline payload generation
- but using those preserved attrs for normal runtime playback/render resolution caused visual regressions in producer CI
- the follow-up fix keeps authored timing available only for Studio payload collection while normal runtime playback continues to resolve from the real live timeline/media state
## Why the later regression fix was needed
The initial runtime change fixed the Apple master timeline, but it also widened timing inference in the core runtime too far. That caused Dockerized producer regressions because rendered visibility started respecting preserved authored timing where it should have relied on the live resolved runtime state.
The latest commit fixes that by splitting the behavior:
- Studio timeline payload: authored timing allowed
- general runtime resolver: authored timing ignored by default
That preserves the Apple master timeline fix without changing producer render semantics.
## Verification
### Local checks
- `bunx oxlint packages/core/src/runtime/init.ts packages/core/src/runtime/startResolver.ts packages/core/src/runtime/timeline.ts packages/core/src/runtime/startResolver.test.ts packages/core/src/runtime/timeline.test.ts packages/studio/vite.config.ts packages/cli/src/server/studioServer.ts`
- `bunx oxfmt --check packages/core/src/runtime/init.ts packages/core/src/runtime/startResolver.ts packages/core/src/runtime/timeline.ts packages/core/src/runtime/startResolver.test.ts packages/core/src/runtime/timeline.test.ts packages/studio/vite.config.ts packages/cli/src/server/studioServer.ts`
- `bun run --filter @hyperframes/core typecheck`
- `bun run --filter @hyperframes/studio typecheck`
- `bun run --filter @hyperframes/cli typecheck`
- `cd packages/core && bun run test src/runtime/startResolver.test.ts src/runtime/timeline.test.ts`
- `bun test packages/cli/src/server/studioServer.test.ts --timeout 20000`
### Browser proof
Tested in Studio with `agent-browser` against the Apple presentation project.
- root/master transport now shows `0:00 / 2:21`
- master clip manifest resolves sequentially (`slide-1 -> slide-2 -> slide-3 ...`)
- seeking to `120s` lands on a late slide instead of a collapsed early timeline state
- after refreshing onto the fresh runtime source, the visible later-slide media advanced correctly in local Studio playback
### CI-equivalent regression proof on devbox
The previously failing producer regressions were rerun on devbox using the same Dockerized path GitHub Actions uses:
- `docker build -f Dockerfile.test -t hyperframes-producer:test .`
- `docker run ... hyperframes-producer:test style-1-prod style-5-prod style-9-prod style-12-prod --sequential`
Those previously failing suites all passed after the runtime split fix:
- `style-1-prod`
- `style-5-prod`
- `style-9-prod`
- `style-12-prod`
## Notes
- the Apple project volume tweak stayed local-only for testing and is not part of this PR
- this PR fixes the master/root timeline bug and the runtime regression it introduced; it does not add general subtimeline authoring support
## Summary
- gate timeline actions to clips Studio can control deterministically
- disable direct move/trim for generic GSAP-timed DOM clips
- add an in-clip `Copy to Agent` fallback for unsupported edits
## Why
Studio should only advertise timeline actions it can round-trip to source HTML with deterministic meaning.
This PR now follows that stricter rule:
- direct move/end-trim are only exposed for clips with a deterministic timeline window
- start trim is only exposed for clips with a real content-offset model
- unsupported motion clips now offer `Copy to Agent` so users still have a fast path to request source-level timing changes
In practice this means generic GSAP-authored DOM clips no longer pretend Studio can rewrite their visible timing just by patching `data-start` / `data-duration`.
## What changed
- added `hasPatchableTimelineTarget()` and `getTimelineEditCapabilities()` in `timelineEditing.ts`
- tightened deterministic-window detection so only media, images, and composition hosts keep direct move/end-trim controls
- kept wrapped media clips editable by recognizing real media metadata even when the host tag is a `div`
- updated `TimelineClip` / `Timeline` to guard interactions with the shared capability model
- added `buildTimelineElementAgentPrompt()` and a `Copy to Agent` fallback button for unsupported clips
- added focused tests for capability derivation and the agent-prompt helper
## Verification
### Automated
- `bun test packages/studio/src/player/components/timelineEditing.test.ts packages/studio/src/player/components/Timeline.test.ts packages/studio/src/player/store/playerStore.test.ts packages/studio/src/utils/sourcePatcher.test.ts`
- `bun run --filter @hyperframes/studio typecheck`
- `bunx oxlint packages/studio/src/player/components/Timeline.tsx packages/studio/src/player/components/timelineEditing.ts packages/studio/src/player/components/timelineEditing.test.ts packages/studio/src/player/components/TimelineClip.tsx`
- `bunx oxfmt --check packages/studio/src/player/components/Timeline.tsx packages/studio/src/player/components/timelineEditing.ts packages/studio/src/player/components/timelineEditing.test.ts packages/studio/src/player/components/TimelineClip.tsx`
### Browser
Verified in Studio with live browser automation against `http://127.0.0.1:4175/#project/timeline-edit-playground`:
- generic GSAP-timed clips (`feature-card`, `title-card`, `prompt-card`) show `Copy to Agent` and no direct move/trim affordances
- wrapped media (`media-card`) still exposes direct controls and remains draggable
- the local playground timings were realigned to match the authored GSAP positions, so preview visibility now matches the timeline windows during manual testing
Recording artifacts used during verification:
- `/tmp/timeline-capabilities-proof/capabilities-flow.webm`
- `/tmp/timeline-capabilities-proof/capabilities-agent-flow.webm`
## Summary
- hide the leading trim handle for timeline clips that cannot offset their own content
- keep leading trim available for media clips backed by playback offset metadata or source duration
- map visual row priority like a normal timeline editor: top timeline rows render above lower rows
## Why This Is Needed
Generic GSAP/DOM timeline clips do not have a playback-offset model like media clips do.
That means a left trim affordance on those clips is misleading today:
- users reasonably expect front trim to remove the beginning of the animation
- the current model can only shorten the clip window, not start the motion halfway through
Instead of exposing a control that implies unsupported behavior, this PR keeps true front trim only on clips that can actually offset their content.
The PR also fixes the stacking convention so the timeline matches normal editor expectations:
- visually higher track row = higher render priority
- visually lower track row = lower render priority
## Current Flow By Element Type
### Generic motion / DOM clips
Examples: `section`, `div`, `aside`, GSAP-driven cards and overlays.
Current supported flow:
- drag the whole clip horizontally to change `data-start`
- right-trim to shorten the end of the clip window
- move between tracks to change `data-track-index`
Not supported yet:
- true front trim that removes the beginning of the animation itself
Behavior after this PR:
- no interactive left trim handle is shown
- right trim still works
- horizontal move still works
### Media clips
Examples: `video` / `audio` clips, or wrappers carrying `data-media-start` / `data-playback-start`.
Current supported flow:
- drag the whole clip horizontally to change `data-start`
- left trim advances clip start and playback offset together
- right trim shortens `data-duration`
Behavior after this PR:
- both left and right trim handles remain available
- left trim persists `data-start` plus `data-media-start` / `data-playback-start`
- right trim persists `data-duration`
## Z-Index Rule
This PR now follows the normal timeline-editor convention:
- top visual row on the timeline = highest `z-index`
- lower visual rows = lower `z-index`
Concretely, because Studio renders tracks in ascending numeric order from top to bottom, lower numeric track values now map to higher `z-index` values.
## Validation
### Automated
- `bun test packages/studio/src/player/components/timelineEditing.test.ts packages/studio/src/player/components/Timeline.test.ts packages/studio/src/player/store/playerStore.test.ts packages/studio/src/utils/sourcePatcher.test.ts`
- `bun run --filter @hyperframes/studio typecheck`
### Browser verification
Verified with `agent-browser` on `timeline-edit-playground`:
- generic motion clips no longer expose an interactive left trim handle
- media clips still expose both trim handles
- left trim on `media-card` persisted `data-start` and `data-media-start`
- right trim on `media-card` persisted `data-duration` only
- moving `title-card` from the bottom row to the top row persisted the highest `z-index` for the top-row clips
- recordings:
- `/tmp/trim-fix-artifacts/trim-flow.webm`
- `/tmp/trim-fix-artifacts/z-index-flow.webm`
## Summary
Add the actual Studio timeline editing layer on top of the preview/runtime foundation.
This PR includes:
- drag-to-move clips across time and tracks
- left/right resize handles with media-aware trim persistence
- edge auto-scroll and edge track creation while dragging
- selector-based source patching for `data-start`, `data-duration`, `data-track-index`, `z-index`, and media trim attributes
- timeline UI cleanup, theming, hover/drag states, and the `Copy Prompt` action
## Why This PR Is Separate
This is the user-facing editing behavior. It depends on the preview/runtime fixes in the base PR, but it is much easier to review once that plumbing is isolated.
## Verification
- `bun run --filter @hyperframes/studio test`
- `bun run --filter @hyperframes/studio typecheck`
- `bunx oxlint packages/studio/src/App.tsx packages/studio/src/components/nle/NLELayout.tsx packages/studio/src/player/components/EditModal.tsx packages/studio/src/player/components/Timeline.tsx packages/studio/src/player/components/TimelineClip.tsx packages/studio/src/player/components/timelineEditing.ts packages/studio/src/player/components/timelineEditing.test.ts packages/studio/src/player/components/timelineTheme.ts packages/studio/src/player/components/timelineTheme.test.ts packages/studio/src/utils/sourcePatcher.ts packages/studio/src/utils/sourcePatcher.test.ts`
- `bunx oxfmt --check packages/studio/src/App.tsx packages/studio/src/components/nle/NLELayout.tsx packages/studio/src/player/components/EditModal.tsx packages/studio/src/player/components/Timeline.tsx packages/studio/src/player/components/TimelineClip.tsx packages/studio/src/player/components/timelineEditing.ts packages/studio/src/player/components/timelineEditing.test.ts packages/studio/src/player/components/timelineTheme.ts packages/studio/src/player/components/timelineTheme.test.ts packages/studio/src/utils/sourcePatcher.ts packages/studio/src/utils/sourcePatcher.test.ts`
## Browser Proof
- verified timeline drag / resize / trim flows in Studio with `agent-browser`
- verified preview hot-refresh behavior without iframe remount flashes
## Stack
- depends on #389
- followed by `fix: smooth scrubber end seeking`
[result.mp4 <span class="graphite__hidden">(uploaded via Graphite)</span> <img class="graphite__hidden" src="https://app.graphite.com/user-attachments/thumbnails/ca71c177-5042-468d-906f-b353938f40f8.mp4" />](https://app.graphite.com/user-attachments/video/ca71c177-5042-468d-906f-b353938f40f8.mp4)
Miguel Ángel