v2.5.0

Added

• jujutsu (jj) as an OPT-IN, colocated git companion. Additive — it never replaces
  git. New jujutsu/config.toml (symlinked to ~/.config/jj/config.toml, in
  core.manifest) sets a sensible colocated-friendly default (ui.default-command = "log",
  auto-local-bookmark; identity intentionally unset — jj does NOT inherit git's
  user.name/user.email, so an opt-in author sets it once with jj config set --user user.name/user.email). tools.zsh gains HAVE_JJ
  detection and aliases.zsh a few HAVE_JJ-guarded verbs (jjs/jjl/jjd); nothing
  is aliased over git. On a box without jj everything is inert. PORTING-MATRIX.md
  documents per-distro packaging (packaged on Arch/openSUSE/Gentoo/Fedora/Homebrew/nix;
  cargo install jujutsu on Alpine(musl)/Debian-Kali — same pattern as yazi/ouch).

Changed

• zsh syntax highlighter swapped: fast-syntax-highlighting →
  zsh-users/zsh-syntax-highlighting (z-sy-h). The pin moves to z-sy-h (a maintained,
  first-party zsh-users plugin) and the load order is corrected per its README: the
  highlighter is now the LAST widget-wrapping plugin sourced, with
  zsh-history-substring-search deferred immediately after it so its widgets get wrapped.
  The FAST_THEME/FAST_HIGHLIGHT theming is replaced by minimal ZSH_HIGHLIGHT_HIGHLIGHTERS
  (main + brackets) and ZSH_HIGHLIGHT_STYLES recoloured to the Tokyo Night Storm palette.
• fleet-drift.sh anchors to the latest released Core tag by default, not the working
  tip. Fan-out stamps each OS repo with the Core tag it carries, so the dashboard now
  measures against the newest vX.Y.Z (via git describe), falling back to
  origin/main/main/HEAD. An explicit --ref/$CORE_REF_SHA still wins. This stops
  the false "BEHIND by N" the report showed for every unreleased commit on main
  (CHANGELOG/auto-tag churn between releases); the fleet-drift.yml workflow drops its
  --ref HEAD accordingly.

Fixed

• auto-tag.sh exit-code contract hardened + tested. Added a defence-in-depth guard so
  _next_version fails loudly (non-zero) on a non-X.Y.Z input instead of producing a
  garbage component, and the call site now propagates that failure rather than tagging a
  bogus v. The behavioral suite (test-core.sh) now asserts the full exit-code contract
  hermetically (no network/gh): success → 0, no-op → 0, validation error → 2, and a real
  create failure (a --push onto an already-taken tag name, tripping Guard 2) → non-zero.

• auto-tag.sh --release fails CI when an opted-in Release create actually fails. The
  gh release create error branch called fail but the script still exited 0, so a real
  failure (gh present, API error) went green with no Release. It now exit 1s there — the
  tag still stands (pushed above), but CI goes red so you create the Release manually. The
  two non-failure exits stay deliberate: gh absent → skip, Release already exists → no-op.
  Also added --release to the usage() synopsis line (it was only in the flag list) and
  clarified its gh/skip semantics.