Three new lint rules that catch structural issues causing compositions
to fail silently in preview:
- root_composition_missing_data_start: Root composition needs data-start="0"
for the runtime to begin playback
- standalone_composition_wrapped_in_template: index.html should not be
wrapped in <template> (only sub-compositions use that)
- root_composition_missing_html_wrapper: index.html needs <!DOCTYPE html>
and <html> wrapper for the bundler
Also adds rawSource to LintContext so rules can inspect pre-template-stripped
HTML, and isSubComposition to linter options so rules can distinguish root
from sub-composition files.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>