Record dest on occupy and retract it when confirmation, verify, or
staging cleanup fails. Restore unmatched quarantine with a no-replace
publish. Event/devapp copy uses mkdir-claim; shell rollback claims dest
before delete. Release copy now says npm/PowerShell create junctions and
Go uses os.Symlink, with copy fallback when linking is unavailable.
The RFC section on filesystems that reject the atomic no-replace rename
still described the retired existence-check-plus-plain-rename fallback
and its accepted race window. The implementation (and the npm and shell
surfaces) claim the destination with mkdir or a hard link — or create
the link directly at the destination — and never release the claim mid
transaction, so a concurrently created object is refused rather than
overwritten. Record that contract and its only relaxed property (child
moves are not all-or-nothing visible) so future maintainers do not
port the racy description back into code.
A universal Agent whose obsolete private copy cannot be retired installs
nothing there, yet every entry point counted that retirement failure as an
install failure — aborting `npm install`, `dws skill setup`, and the shell
installers even when the canonical store and all links published correctly,
and skipping the skills-state write. Route retirement failures to a separate
warning path across all surfaces (Go upgrade + skill setup, npm, PowerShell,
install.sh, install-skills.sh, install-event.sh, install-devapp.sh).
Also:
- Add a checked-rename fallback for filesystems that reject the atomic
no-replace flag (NFS, FUSE, overlayfs); the no-clobber contract is kept and
the previously unsupported platforms build and work.
- PowerShell multi-mode links only bundle skills, never the shared canonical
store, so third-party/user skills are no longer fanned into every Agent root.
- Prune ~/.dws/skill-backups to the newest 5 on every surface; encode
HOME-relative backup names on PowerShell to preserve origin.
- Add simulated-win32 junction coverage and rewrite the tautological
no-replace test; remove dead code whose tests gave false coverage.
- Soften the overstated Windows ownership-proof comment (NTFS tunneling).
Dennis