Validate final selected skill roots and references before preview, approval, and client/Hopper changes, with a repeated installation-boundary check. Preserve interactive unselected-client choices and registration-only setup. Share typed directory/read observations across setup, doctor, and update; report unmanaged paths and unknown reads with actionable paths/reasons. Retain uninstall child outcomes and ownership manifests when cleanup remains. Shared single-pass inspection retains all unreadable paths after stale or missing files and keeps observed metadata, without duplicate manifest reads. Absent installed files do not depend on generated bundled bytes. Validation: 217 related tests, 41 final CLI/MCP and filesystem checks, and all 7,446 source tests in 508 files pass (eight platform/condition skips). Static/docs checks pass. Normal four-call install/rerun/repair/uninstall tasks preserve results and output token counts. No native Windows follow-up or arbitrary concurrent swap containment claim. Fixes #3057. Co-authored-by: geekwolf <3125615+geekwolf@users.noreply.github.com> Co-authored-by: N0zoM1z0 <161784452+N0zoM1z0@users.noreply.github.com> Co-authored-by: Kaoru0822 <208281322+kaoru0822-kitauji@users.noreply.github.com> Co-authored-by: akushonkamen <74654766+akushonkamen@users.noreply.github.com>