Summary

Adds a missing_data_no_timeline lint rule to @hyperframes/core's composition linter.

Why

The producer polls window.__timelines[id] for up to 45 seconds waiting for a GSAP timeline to register before starting render. Compositions that never register a timeline (static compositions, pure-CSS animations, etc.) stall every render with a 45-second timeout before the producer gives up and proceeds. The fix is trivially cheap — data-no-timeline on the root element tells the producer to skip the poll entirely — but authors have no signal that they're paying this cost.

This rule surfaces the problem at lint time so it can be caught before render.

What changed

packages/core/src/lint/rules/composition.ts

• New rule: missing_data_no_timeline
• Fires as a warning when:
  • Composition has a data-composition-id root
  • No script in the composition calls window.__timelines[
  • Root element does NOT already have data-no-timeline
• Provides a fixHint pointing to the exact attribute to add

packages/core/src/lint/rules/composition.test.ts

• 38 new tests covering the new rule: fires when timeline missing, suppressed when data-no-timeline present, suppressed when window.__timelines registration found

Test plan

• bun run test packages/core → all 1559 tests pass including 38 new rule tests