* 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
Own safety/gates/parameters in metadata/ and Agent prose in selection/,
drop the monolithic Manual file, and keep confirmation aligned with
per-tool runtime_gate.
Co-authored-by: Cursor <cursoragent@cursor.com>