Address the two P1 review findings and the coverage-gate CI failures:
- Every install/upgrade path that removes a skill dir (opposite-mode
leftovers, stale dingtalk-* / dws-shared, and same-name refreshes) now
moves the directory to ~/.dws/skill-backups/<stamp>/ first across
install.sh, install-skills.sh, install.ps1, install.js, `dws skill
setup`, and `dws upgrade`. A backup failure preserves the original
directory and never removes it.
- Remove --yes from every copyable `dws skill setup` example and document
what the command may remove; add regression tests that declining the
confirmation performs no removal and that the confirmation previews
every directory slated for backup+removal.
- Rename the skill-mode tests to the TestCrossPlatformCoverage* prefix so
the platform coverage gate selects them, and add edge tests for the
backup/prune/cleanup fallback branches, restoring changed-code coverage
to 100%.
Co-authored-by: Cursor <cursoragent@cursor.com>
