UI recording timeline

Produces a self-contained folder with index.html and the video. The video fills the window. Below it are a one-line caption and a thin timeline (phase colors, paint ticks, hover thumbnails, scrubbing). Change regions flash on the video at each paint, and a paint list drawer opens with l.

Everything needed is in this skill directory:

• scripts/timeline.py: one CLI with all the steps. Dependencies are declared inline, and uv run installs them.
• assets/template.html: the page. build injects the data into it.

Requirements: ffmpeg/ffprobe and uv on PATH. Chrome or Chromium is needed only for preview.

Below, T means uv run <this skill dir>/scripts/timeline.py. Define it as a shell function, not a variable: zsh doesn't word-split variables. Use the absolute path of the skill directory:

T(){ uv run "/abs/path/to/ui-recording-timeline/scripts/timeline.py" "$@"; }

WD is the output folder. If the user's project has conventions for where research or collateral goes, follow them; otherwise put WD next to the video as <video-stem>-timeline/.