* fix: surface invalid sheet and todo targets
* docs: record invalid target fixes
* fix: expose todo attachment listing schema
* fix: make Windows helper coverage portable
* test: run quality regressions in platform coverage
Merge upstream main and publish the three public audit leaves into the
CommandRegistry, metadata/selection hints, and regenerated Catalog so
reverse completeness stays green.
Co-authored-by: Cursor <cursoragent@cursor.com>