[wanjinhao1]

What

The linter now reports invalid-duration and invalid-track-index timing diagnostics (already produced by the parser in compositionContract.ts) as findings, so values like data-duration="2s" or data-duration="-3" no longer lint clean.

Why

The parser marks some data-duration / data-track-index values as invalid, but the linter only turned deprecated-layer, deprecated-end and conflicting-end into findings, so a clip silently got a different duration/track than the author wrote.

Fixes #7272

Related work

Fixes #7272 (mentor @jrusso1020; claimed in the issue before starting, as requested).

How

Added a rule in packages/lint/src/rules/composition.ts that walks readTagTiming(tag.raw).diagnostics and maps invalid-duration → invalid_data_duration and invalid-track-index → invalid_data_track_index (both severity: "error"). Messages include the element (tag + id when present) and the rejected attribute/value; fixHint says what a valid value looks like. No parser changes.

Test plan

• Unit tests added/updated — new tests in composition.test.ts: "2s" and "-3" report invalid_data_duration, a valid data-duration="2" reports nothing, and data-track-index="1.5" reports invalid_data_track_index (vitest run packages/lint/src/rules/composition.test.ts: all new tests pass)
• Manual testing performed
• Documentation updated (if applicable) — no docs changes needed; lint finding codes are not enumerated in docs
• Comments follow CONTRIBUTING.md "Comments"

[jrusso1020]

Thanks for contributing this fix. I reviewed the competing submissions and selected #7286, which includes the parser-based duration checks, element/value/severity regression cases, and documentation for both new lint codes. Closing this as a duplicate so the issue has one implementation to take through CI and merge: #7286. This is consolidation of overlapping work, not a rejection of your contribution.