Tighten uninstall auto-detection so it only falls back to the legacy
sync-ecc-to-codex.sh path when there is an ownership manifest
(~/.codex/ecc/legacy-sync-state.json) or an ECC marker block in
~/.codex/AGENTS.md. Previously a clean Codex home with unrelated prompt
files could be misclassified as a legacy install, causing uninstall to
skip normal install-state reconciliation and exit with a partial warning.
Also make the no-state fallback return 'not-found' when there is no
marker to remove and no candidate files to clean, and make explicit
--legacy-codex-sync report the same on a clean home.
Co-Authored-By: Paperclip <noreply@paperclip.ing>
