3a424c6f73
Adds CoverageRollup type, getCoverageRollup() against /api/admin/library/coverage, and createCoverageQuery() with the same 3s/30s pacing used by scan-status. New qk.coverage() key follows the existing zero-arg tuple pattern. Vitest covers the GET path and the empty-library zero-state plus the with_art + pending + settled = total invariant.