First PR in the Studio storyboarding stack. Establishes the parseable
contract the storyboard UI reads from; no UI yet.
- core/storyboard: StoryboardManifest/Frame/Globals types + a lenient
STORYBOARD.md parser (frontmatter + status/src/duration/transition_in,
freeform narrative tolerated, never throws, records warnings). Exposed as
@hyperframes/core/storyboard (browser-safe).
- studio-api: GET /projects/:id/storyboard returns the normalized manifest
with per-frame srcExists; missing file -> exists:false, not 404.
- fixture: packages/studio/fixtures/storyboard-sample for dogfooding the
storyboard view in later PRs (built/animated frames + one outline).
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>