The daemon pins each agent CLI's symlink-resolved absolute path at startup to
block PATH-redirect of a task launch. A version manager (Homebrew Cask, nvm/fnm)
upgrading in place deletes the pinned versioned directory and repoints the stable
name, leaving the daemon on a path that no longer exists — every codex task, model
list, and version detection then hard-fails with "executable not found" until the
daemon restarts.
resolveAgentEntry now self-heals a vanished pin by re-resolving the recorded
command once, version-detecting and min-version-gating the candidate before
adopting it, and publishing {path, version} atomically so callers key policy off
the binary that actually runs. Coalesced with singleflight; a live heal wins over
a reappearing stale path; custom runtimes and custom-only hosts are untouched.
Applied at task launch, model listing, and registration.
MUL-4486
