Add @chenglou/pretext dependency and fitTextFontSize() utility that uses
canvas measureText to compute the largest font size that fits text within
a given width. Replaces character-count heuristics with actual font-aware
measurement.
- New fitTextFontSize() in @hyperframes/core/text, exposed on window.__hyperframes
- Generalized for all text elements (captions, titles, etc.), not just captions
- Unit tests (mocked pretext) + browser integration test (real Chromium canvas)
- Updated captions skill docs with usage, exit guarantee, and self-lint patterns
Co-authored-by: James <james.russo@heygen.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
