feat(gates): enforce metadata.version bumps on changed skills at pre-push

check-skill-version-bump fails a push when a skill directory changed
against its merge-base with main (tests/ excluded) without a strictly
higher metadata.version than main. New, renamed and deleted skills are
exempt; every plugin is covered. Recorded as a dated section in
ADR-0022 and documented in gates.md.

Patch-bumps the 17 skills that changed on this branch without a bump,
so the branch passes its own gate. Simplification audit finding 33.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

.pre-commit-config.yaml

@@ -192,6 +192,19 @@ repos:
         pass_filenames: false
         always_run: true
 
+      - id: check-skill-version-bump
+        name: Check changed skills bump metadata.version
+        description: On every push, fail if a skill directory changed (tests/ excluded) since the merge-base with main without its SKILL.md metadata.version rising (ADR-0022)
+        entry: bash scripts/check-skill-version-bump.sh
+        language: system
+        stages: [pre-push]
+        pass_filenames: false
+        always_run: true
+        # Baseline is the merge-base with origin/main (falling back to main),
+        # not the remote branch tip: readers install from main. Fails closed
+        # when no main ref resolves. Merges through Gitea's merge button run no
+        # local hook, so they bypass this, just as they bypass check-release-needed.
+
       - id: validate-marketplace
         name: Validate marketplace manifest
         description: Run claude plugin validate --strict on the root marketplace manifest

docs/adr/0022-skill-metadata-version-is-mandatory.md

@@ -76,3 +76,39 @@ own SKILL.md drops the "with `metadata.version` present" conditional in its bump
 presence is no longer in question. `.pre-commit-config.yaml`'s `skill-frontmatter` hook is extended
 to require the field, closing the gap #113 and #118 both named in the same audit pass: a stated rule
 with nothing enforcing it drifts the same way an unstated one does.
+
+## Amendment (2026-09-16) — the bump is enforced at push, not only required to exist
+
+**Context.** Making the field mandatory did not make it move. The only thing that bumped it was
+`skill-author` Step 4, so every hand edit and every trim pass skipped the bump: on
+`docs/simplification-audit`, 17 of the 40 skill directories that changed against `main` carried
+the same `metadata.version` as `main`, and `gitea` alone sat at six different values. Both
+validators checked presence and semver shape, never movement, so the field could not answer the
+question this ADR gives it — "did this change since I last read it". (Simplification audit
+finding 33.)
+
+**Decision.** `scripts/check-skill-version-bump.sh` runs as a pre-push hook on every push. For each
+skill directory under `plugins/*/.apm/skills/` that differs between the pushed ref and its
+merge-base with `main`, ignoring `tests/`, the pushed `metadata.version` must be strictly greater
+than `main`'s.
+
+- **Baseline is the merge-base with `main`, not the previous commit.** Readers only ever see
+  `main` — installs resolve against the default branch (ADR-0018) — so one bump per branch is what
+  the field owes them. A per-commit check would bump a skill once per commit and inflate the
+  number past meaning.
+- **"Greater", not "exactly one patch higher".** A second `skill-author` pass on the same branch
+  that bumps again still passes.
+- **`tests/` is excluded.** No agent loads it; a fixture-only change does not change the skill.
+- **Skills absent from either side are exempt.** New, renamed and merged skills start fresh under
+  the rules above; deleted skills have nothing to check.
+- **Every plugin is covered, `bin` included,** and the gate is repo-local — it is not exported
+  through `.pre-commit-hooks.yaml`.
+
+**Considered options.** *Declare the field advisory* — cheapest, but concedes the field cannot do
+its job. *Drop the field* — rejected by this ADR already, and costlier now. *Check at commit
+time against `HEAD`* — rejected for the inflation above.
+
+**Consequences.** The 17 unbumped skills took a patch bump in the commit that added the gate.
+Like `check-release-needed`, the gate only fires on a local `git push` through pre-commit: a merge
+made with Gitea's merge button runs no local hooks and is not checked. A typo fix in a skill now
+costs a version bump; that is the rule working, not noise.

docs/spec/gates.md

@@ -21,24 +21,24 @@ Install hooks via `pc-run`, wiring **all three stages**. This repo's `.pre-commi
 `default_install_hook_types`, so a plain install silently skips `commit-msg` (Conventional Commits)
 and `pre-push` (everything below).
 
-The pre-push command reports **10** hooks, not 8. The extra two are pre-commit's own `meta` hooks,
+The pre-push command reports **11** hooks, not 9. The extra two are pre-commit's own `meta` hooks,
 `check-hooks-apply` and `check-useless-excludes`: they declare no `stages:`, so they run at every
 stage including this one. Both are declared in this repo's `.pre-commit-config.yaml` like everything
-else — what separates them is `repo: meta` (pre-commit's own built-ins) from `repo: local`. Eight
+else — what separates them is `repo: meta` (pre-commit's own built-ins) from `repo: local`. Nine
 is the count of hooks this repo authors itself.
 
-**The caveat: one of those 8 is a silent no-op under that invocation.**
+**The caveat: one of those 9 is a silent no-op under that invocation.**
 `check-release-needed` exits 0 immediately unless `PRE_COMMIT_REMOTE_BRANCH` equals
 `refs/heads/main`, and pre-commit exports that variable only from the real pre-push git hook during
 an actual `git push`. Running the stage by hand — or from a CI runner — therefore reports it
 `Passed` having checked nothing. That is by design for feature branches — pushing WIP must not be
 blocked on cutting a premature tag — but it means `--hook-stage pre-push --all-files` is a full
-rehearsal of 7 hooks and a skip of the eighth. The script's own header records the same gap for
+rehearsal of 8 hooks and a skip of the ninth. The script's own header records the same gap for
 a PR merged through Gitea's merge button, where no local push happens at all.
 
 ## The pre-push gate
 
-Eight hooks, grouped below by what they guard rather than by the order `.pre-commit-config.yaml` declares them in.
+Nine hooks, grouped below by what they guard rather than by the order `.pre-commit-config.yaml` declares them in.
 
 **Core checks**
 
@@ -80,12 +80,30 @@ drift in generated text.
 | Hook | Guards |
 |---|---|
 | `check-release-needed` | on a real `git push` to `main` only — fails if files exposed via `.pre-commit-hooks.yaml` changed since the last tag. A no-op everywhere else, including under `pre-commit run --hook-stage pre-push` (see [the caveat above](#running-the-gates)) |
+| `check-skill-version-bump` | on every push — fails if a skill directory changed since the merge-base with `main` without its `metadata.version` rising (see [below](#check-skill-version-bump)) |
 
 Two of these shell out to `apm`: `apm-audit-ci` and `apm-pack-check-clean`. The second is a bare
 `apm …` entry and the first is a `bash -c` loop calling `apm` once per package, so without the CLI
 the push dies with an unhelpful "command not found". Install with `apm-install`, or
 `curl -sSL https://aka.ms/apm-unix | sh`; verify with `apm --version`.
 
+### `check-skill-version-bump`
+
+ADR-0022 makes `metadata.version` mandatory and a skill change carries a bump; `skill-size-check`
+only checks the field's presence and shape, so this hook holds the bump itself.
+
+- **Baseline is `git merge-base origin/main <pushed ref>`** (local `main` if `origin/main` does not
+  resolve). Readers install from `main`, so "changed" means changed against what `main` ships. The
+  remote branch tip is not the baseline: a second push would excuse an unbumped change the first
+  push already carried. With no `main` ref or no merge-base, the hook fails closed.
+- **A changed skill must end strictly above its baseline version**, compared numerically
+  (`1.0.10` > `1.0.9`). Any bump size passes. A missing or non-`MAJOR.MINOR.PATCH` version at the
+  pushed ref fails. Skills absent at the baseline (new, renamed, merged) or at the pushed ref
+  (deleted) are exempt.
+- **`<skill>/tests/` is excluded**: no agent loads it, so a test-only change ships nothing.
+- **Known gap:** a PR merged through Gitea's merge button runs no local hook, the same gap
+  `check-release-needed` has.
+
 ## Skill and agent context gates (ADR-0020)
 
 The `skill-size-check` pre-commit hook, scoped to `^plugins/[^/]+/\.apm/skills/[^/]+/SKILL\.md$`,

plugins/bin/.apm/skills/caveman/SKILL.md

@@ -5,7 +5,7 @@ description: >
   Ultra-compressed output mode that drops articles, filler and pleasantries while
   keeping technical substance exact, cutting token usage by roughly 75%.
 metadata:
-  version: "1.0.0"
+  version: "1.0.1"
 ---
 
 Respond terse like smart caveman. All technical substance stay. Only fluff die.

plugins/bin/.apm/skills/grill-me/SKILL.md

@@ -6,7 +6,7 @@ description: >
   decision tree. Not a plan to challenge against `CONTEXT.md` and ADRs ->
   `grill-with-docs`.
 metadata:
-  version: "1.0.0"
+  version: "1.0.1"
 ---
 
 Interview me relentlessly about every aspect of this plan until we reach a shared understanding. Walk down each branch of the design tree, resolving dependencies between decisions one-by-one. For each question, provide your recommended answer.

plugins/bin/.apm/skills/grill-with-docs/SKILL.md

@@ -5,7 +5,7 @@ description: >
   the interview challenges terms against `CONTEXT.md` and writes decisions into
   it and into ADRs as they land. Not a plain interview -> `grill-me`.
 metadata:
-  version: "1.0.0"
+  version: "1.0.1"
 ---
 
 <what-to-do>

plugins/bin/.apm/skills/prototype/SKILL.md

@@ -6,7 +6,7 @@ description: >
   variations. Not production code -> `tdd`. Not talking a design through ->
   `grill-me`.
 metadata:
-  version: "1.0.0"
+  version: "1.0.1"
 ---
 
 # Prototype

plugins/bin/.apm/skills/research/SKILL.md

@@ -6,7 +6,7 @@ description: >-
   documentation written from existing code or specs -> `write-docs`. Not a bug
   or incident -> `diagnose`.
 metadata:
-  version: "1.0.0"
+  version: "1.0.1"
   category: research
 allowed-tools:
   - Grep

plugins/bin/.apm/skills/write-docs/SKILL.md

@@ -9,7 +9,7 @@ description: >
 updated: 2026-05-17
 when: invoked by explicit trigger ("write docs for X", "document this module", "create docs for this feature") or implicit request to produce technical documentation from code or spec
 metadata:
-  version: "1.0.0"
+  version: "1.0.1"
   category: implement
 source:
   - repo: anthropics/skills

plugins/core/.apm/skills/agentsmd-audit/SKILL.md

@@ -14,7 +14,7 @@ metadata:
     - context7-websites-agents-md
     - context7-agentsmd-agents-md
     - governance-secrets-hard-prohibition
-  version: "0.1.2"
+  version: "0.1.3"
 ---
 
 ## Gotchas

plugins/core/.apm/skills/agentsmd-author/SKILL.md

@@ -12,7 +12,7 @@ metadata:
     - agents-md-official
     - context7-websites-agents-md
     - context7-agentsmd-agents-md
-  version: "0.1.2"
+  version: "0.1.3"
 ---
 
 ## Gotchas

plugins/core/.apm/skills/provider-adapter-author/SKILL.md

@@ -11,7 +11,7 @@ metadata:
   category: docs
   source_keys:
     - adr-0002-0003-two-tier-claude-md
-  version: "0.1.1"
+  version: "0.1.2"
 ---
 
 ## Gotchas

plugins/git/.apm/skills/git-submodules/SKILL.md

@@ -9,7 +9,7 @@ description: >
   Not the superproject's own remotes -> `git-remotes`.
 
 metadata:
-  version: "1.0.0"
+  version: "1.0.1"
   category: git
   source_keys:
     - git-scm-submodule-docs

plugins/git/.apm/skills/pc-author/SKILL.md

@@ -6,7 +6,7 @@ description: >
   shellcheck"). Not running, installing, or updating hooks -> `pc-run`.
 allowed-tools: Bash Read Write Edit
 metadata:
-  version: "1.0.0"
+  version: "1.0.1"
   category: devtools
   source_keys:
     - context7-pre-commit-com

plugins/git/.apm/skills/pc-run/SKILL.md

@@ -8,7 +8,7 @@ description: >
 compatibility: Requires pre-commit installed and available on PATH.
 
 metadata:
-  version: "1.0.1"
+  version: "1.0.2"
   category: devtools
   source_keys:
     - context7-pre-commit-com

plugins/gitea/.apm/skills/gitea-branches/SKILL.md

@@ -12,7 +12,7 @@ compatibility: Requires Gitea MCP server configured with a token with write:repo
 
 metadata:
   category: integration
-  version: "0.1.3"
+  version: "0.1.4"
   source_keys:
     - gitea-mcp-repo
     - gitea-mcp-slim-go

plugins/kyberforge/.apm/skills/apm-install/SKILL.md

@@ -6,7 +6,7 @@ description: >
   authoring, publishing, auditing, or dependency installation for an apm
   package -> `apm-workflow`.
 metadata:
-  version: "1.0.0"
+  version: "1.0.1"
   category: apm
   source_keys:
     - context7-microsoft-apm

plugins/kyberforge/.apm/skills/apm-workflow/SKILL.md

@@ -5,7 +5,7 @@ description: >
   the dependencies it declares, or an apm marketplace — even when the user does
   not say "apm". Not the apm binary or an agent runtime -> `apm-install`.
 metadata:
-  version: "1.0.0"
+  version: "1.0.1"
   category: apm
   source_keys:
     - context7-microsoft-apm

plugins/lint/.apm/skills/vale-config/SKILL.md

@@ -8,7 +8,7 @@ description: >
 
 metadata:
   category: lint
-  version: "0.1.2"
+  version: "0.1.3"
   source_keys:
     - context7-websites-vale-sh
     - house-vale-3-15-2-repro

plugins/lint/.apm/skills/vale-run/SKILL.md

@@ -6,7 +6,7 @@ description: >
   as in "lint the docs", "check prose style", or "why is CI failing on the docs
   check". Not setting up Vale config or styles -> `vale-config`.
 metadata:
-  version: "0.1.3"
+  version: "0.1.4"
   category: lint
   source_keys:
     - context7-websites-vale-sh

scripts/check-skill-version-bump.sh

@@ -0,0 +1,156 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Fails a push when a skill changed without its SKILL.md `metadata.version`
+# being bumped. ADR-0022 makes the field mandatory and the bump the rule; this
+# is the gate that holds the rule, since skill-size-check only checks presence
+# and shape.
+#
+# Baseline: `git merge-base <main> <pushed ref>`. Readers install skills from
+# main, so "changed" means changed relative to what main ships, not relative to
+# the remote branch's current tip. Diffing from PRE_COMMIT_FROM_REF would let
+# the second push of a feature branch excuse a change the first push already
+# carried unbumped. Unlike check-release-needed this runs on EVERY push, not
+# only pushes to main: a missing bump is cheapest to fix on the branch, before
+# review, and a push to main is then already covered.
+#
+# Scope: every skill directory plugins/<plugin>/.apm/skills/<skill>/, bin
+# included. Anything under <skill>/tests/ is ignored — no agent ever loads it,
+# so a test-only change ships nothing to a reader. A skill counts as changed
+# when any other file under its directory differs between baseline and pushed
+# ref. Renames are diffed as delete + add (--no-renames), so:
+#   - a skill absent at the baseline (new, renamed-to, merged-into) is exempt;
+#     it has no prior version to exceed.
+#   - a skill absent at the pushed ref (deleted, renamed-from) is exempt;
+#     there is nothing left to version.
+# A changed skill present at both refs must carry a three-part semver
+# `metadata.version` at the pushed ref (same SEMVER_RE as skill-size-check.sh,
+# so pre-release suffixes are rejected here as they are there) that is
+# numerically greater than the baseline's. A baseline with no parseable
+# version (a skill predating ADR-0022) accepts any valid version. Versions are
+# read from git objects, never the working tree.
+#
+# Missing baseline: if neither origin/main nor main resolves, or no merge-base
+# exists (shallow clone, unrelated history), the gate FAILS closed — the same
+# choice check-release-needed makes for an unreadable tag. Passing would make
+# a fresh clone without main the one place the rule is silently off.
+#
+# Known gap: this only fires on a local `git push` through pre-commit's
+# pre-push hook (or a manual `pre-commit run --hook-stage pre-push`). A PR
+# merged via Gitea's merge button runs no local hook at all — closing that
+# requires a server-side CI job, which this repo does not have yet.
+
+# See check-release-needed.sh: PRE_COMMIT_TO_REF is the local sha actually
+# being pushed, which is only HEAD for the common case.
+PUSHED_REF="${PRE_COMMIT_TO_REF:-HEAD}"
+
+# All-zeros sha: the push deletes a branch. Nothing ships; bail out.
+if [[ "$PUSHED_REF" =~ ^0+$ ]]; then
+  exit 0
+fi
+
+REPO_ROOT="$(git rev-parse --show-toplevel)"
+cd "$REPO_ROOT"
+
+MAIN_REF=""
+for candidate in origin/main main; do
+  if git rev-parse --verify -q "$candidate^{commit}" > /dev/null; then
+    MAIN_REF="$candidate"
+    break
+  fi
+done
+
+if [[ -z "$MAIN_REF" ]]; then
+  echo "FAIL: neither origin/main nor main resolves, so there is no baseline to compare skill versions against." >&2
+  echo "  Fix: git fetch origin main (or create a local main) and retry." >&2
+  exit 1
+fi
+
+if ! BASELINE="$(git merge-base "$MAIN_REF" "$PUSHED_REF" 2>/dev/null)"; then
+  echo "FAIL: no merge-base between $MAIN_REF and $PUSHED_REF, so there is no baseline to compare skill versions against." >&2
+  echo "  Fix: ensure full history is available (e.g. git fetch --unshallow) and retry." >&2
+  exit 1
+fi
+
+if ! CHANGED="$(git diff --no-renames --name-only "$BASELINE" "$PUSHED_REF" -- plugins)"; then
+  echo "FAIL: could not diff $BASELINE..$PUSHED_REF (see git error above)." >&2
+  exit 1
+fi
+
+SKILL_PATH_RE='^(plugins/[^/]+/\.apm/skills/[^/]+)/(.+)$'
+SKILL_DIRS=()
+while IFS= read -r path; do
+  [[ "$path" =~ $SKILL_PATH_RE ]] || continue
+  [[ "${BASH_REMATCH[2]}" == tests/* ]] && continue
+  dir="${BASH_REMATCH[1]}"
+  seen=false
+  for existing in ${SKILL_DIRS[@]+"${SKILL_DIRS[@]}"}; do
+    [[ "$existing" == "$dir" ]] && { seen=true; break; }
+  done
+  $seen || SKILL_DIRS+=("$dir")
+done <<< "$CHANGED"
+
+[[ ${#SKILL_DIRS[@]} -eq 0 ]] && exit 0
+
+# Prints the three-part semver metadata.version from SKILL.md on stdin, or
+# nothing when it is missing or malformed. Same acceptance rule as
+# skill-size-check.sh: str()-coerce, strip whitespace and quotes, then
+# ^\d+\.\d+\.\d+$ — so `1.0` (a YAML float) and `1.0.0-rc1` both print nothing.
+read_version() {
+  python3 -c '
+import re, sys, yaml
+text = sys.stdin.read()
+m = re.match(r"^---\s*\n(.*?)\n---\s*(\n|$)", text, re.S)
+if not m:
+    sys.exit(0)
+try:
+    data = yaml.safe_load(m.group(1))
+except Exception:
+    sys.exit(0)
+meta = data.get("metadata") if isinstance(data, dict) else None
+ver = meta.get("version") if isinstance(meta, dict) else None
+if ver is None:
+    sys.exit(0)
+ver = str(ver).strip().strip("\x27\"")
+if re.match(r"^\d+\.\d+\.\d+$", ver):
+    print(ver)
+'
+}
+
+# Exit 0 when $1 > $2, both MAJOR.MINOR.PATCH, compared numerically so
+# 1.0.10 > 1.0.9. 10# forces base 10 on a leading zero.
+semver_gt() {
+  local -a a b
+  local i
+  IFS=. read -ra a <<< "$1"
+  IFS=. read -ra b <<< "$2"
+  for i in 0 1 2; do
+    if (( 10#${a[i]} > 10#${b[i]} )); then return 0; fi
+    if (( 10#${a[i]} < 10#${b[i]} )); then return 1; fi
+  done
+  return 1
+}
+
+OFFENDERS=()
+for dir in ${SKILL_DIRS[@]+"${SKILL_DIRS[@]}"}; do
+  # Absent at baseline: new, renamed-to, or merged-into. Exempt.
+  git cat-file -e "$BASELINE:$dir/SKILL.md" 2>/dev/null || continue
+  # Absent at pushed ref: deleted or renamed-from. Exempt.
+  [[ "$(git cat-file -t "$PUSHED_REF:$dir" 2>/dev/null)" == "tree" ]] || continue
+
+  base_ver="$(git show "$BASELINE:$dir/SKILL.md" | read_version)"
+  cur_ver="$(git show "$PUSHED_REF:$dir/SKILL.md" 2>/dev/null | read_version || true)"
+
+  if [[ -z "$cur_ver" ]]; then
+    OFFENDERS+=("$dir: metadata.version missing or not MAJOR.MINOR.PATCH at $PUSHED_REF (baseline: ${base_ver:-none})")
+  elif [[ -n "$base_ver" ]] && ! semver_gt "$cur_ver" "$base_ver"; then
+    OFFENDERS+=("$dir: $base_ver -> $cur_ver")
+  fi
+done
+
+if [[ ${#OFFENDERS[@]} -gt 0 ]]; then
+  echo "FAIL: skills changed since merge-base with $MAIN_REF without a metadata.version bump (ADR-0022):" >&2
+  printf '    %s\n' ${OFFENDERS[@]+"${OFFENDERS[@]}"} >&2
+  echo "  Fix: raise metadata.version in each SKILL.md above the baseline — bump PATCH at minimum." >&2
+  exit 1
+fi

tests/test-skill-version-bump.sh

@@ -0,0 +1,252 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+SCRIPT="$REPO_ROOT/scripts/check-skill-version-bump.sh"
+PASS=0
+FAIL=0
+
+pass() { echo "  PASS: $1"; PASS=$((PASS + 1)); }
+fail() { echo "  FAIL: $1"; FAIL=$((FAIL + 1)); }
+
+# The gate reads versions with python3 + PyYAML, the same hard requirement
+# skill-size-check carries. Without them this suite cannot run: exit 77 so
+# run-tests reports SKIPPED (and --strict fails the push).
+if ! python3 -c 'import yaml' 2>/dev/null; then
+  echo "SKIP: python3 with PyYAML is required" >&2
+  exit 77
+fi
+
+# Output assertions use here-strings, never `echo | grep -q` (pipefail race;
+# see tests/test-check-release-needed.sh).
+
+CLEANUP_DIRS=()
+trap 'rm -rf ${CLEANUP_DIRS[@]+"${CLEANUP_DIRS[@]}"}' EXIT
+
+# write_skill <repo> <plugin> <skill> <version-line|""> [body]
+# An empty version line writes a SKILL.md with no metadata block at all.
+write_skill() {
+  local repo="$1" plugin="$2" skill="$3" vline="$4" body="${5:-body}"
+  local d="$repo/plugins/$plugin/.apm/skills/$skill"
+  mkdir -p "$d"
+  {
+    echo "---"
+    echo "name: $skill"
+    echo "description: Use when testing."
+    if [[ -n "$vline" ]]; then
+      echo "metadata:"
+      echo "  $vline"
+    fi
+    echo "---"
+    echo "$body"
+  } > "$d/SKILL.md"
+}
+
+commit() { (cd "$1" && git add -A && git commit -q -m "${2:-change}"); }
+
+# A fixture with skills alpha (1.0.0) and beta (1.0.9) on main, then checked out
+# onto a feature branch.
+make_fixture() {
+  local dir
+  dir="$(mktemp -d)"
+  CLEANUP_DIRS+=("$dir")
+  (cd "$dir" && git init -q -b main && git config user.email t@t.t && git config user.name t)
+  write_skill "$dir" demo alpha 'version: "1.0.0"'
+  write_skill "$dir" demo beta "version: 1.0.9"
+  commit "$dir" initial
+  (cd "$dir" && git checkout -q -b feature)
+  echo "$dir"
+}
+
+# Every PRE_COMMIT_* input comes from here: a value inherited from the pre-push
+# hook running this suite names a sha of the real repo, not the fixture.
+run_check() {
+  local dir="$1"
+  if [[ $# -ge 2 ]]; then
+    (cd "$dir" && unset PRE_COMMIT_FROM_REF PRE_COMMIT_REMOTE_BRANCH \
+      && PRE_COMMIT_TO_REF="$2" bash "$SCRIPT" 2>&1)
+  else
+    (cd "$dir" && unset PRE_COMMIT_FROM_REF PRE_COMMIT_TO_REF PRE_COMMIT_REMOTE_BRANCH \
+      && bash "$SCRIPT" 2>&1)
+  fi
+}
+
+# expect_pass <desc> <dir> [to-ref]
+expect_pass() {
+  local desc="$1"; shift
+  local out
+  if out="$(run_check "$@")" && [[ -z "$out" ]]; then
+    pass "$desc"
+  else
+    fail "$desc — expected silent exit 0, got: $out"
+  fi
+}
+
+# expect_fail <desc> <pattern> <dir> [to-ref]
+expect_fail() {
+  local desc="$1" pattern="$2"; shift 2
+  local out
+  if out="$(run_check "$@")"; then
+    fail "$desc — expected non-zero exit, got 0"
+  elif grep -qE "$pattern" <<< "$out"; then
+    pass "$desc"
+  else
+    fail "$desc — output did not match /$pattern/: $out"
+  fi
+}
+
+echo ""
+echo "--- 1. unchanged skill passes ---"
+F="$(make_fixture)"
+echo "unrelated" > "$F/README.md"; commit "$F"
+expect_pass "no skill change passes silently" "$F"
+
+echo ""
+echo "--- 2. changed without bump fails ---"
+F="$(make_fixture)"
+write_skill "$F" demo alpha 'version: "1.0.0"' "new body"; commit "$F"
+expect_fail "unbumped change fails and names baseline and current" "alpha: 1\.0\.0 -> 1\.0\.0" "$F"
+
+echo ""
+echo "--- 3. changed with patch / minor / major bump passes ---"
+for v in 1.0.1 1.1.0 2.0.0; do
+  F="$(make_fixture)"
+  write_skill "$F" demo alpha "version: \"$v\"" "new body"; commit "$F"
+  expect_pass "bump to $v passes" "$F"
+done
+
+echo ""
+echo "--- 4. version decreased fails ---"
+F="$(make_fixture)"
+write_skill "$F" demo beta "version: 1.0.8" "new body"; commit "$F"
+expect_fail "decrease fails" "beta: 1\.0\.9 -> 1\.0\.8" "$F"
+
+echo ""
+echo "--- 5. change to a non-SKILL.md file still counts ---"
+F="$(make_fixture)"
+mkdir -p "$F/plugins/demo/.apm/skills/alpha/references"
+echo "ref" > "$F/plugins/demo/.apm/skills/alpha/references/x.md"; commit "$F"
+expect_fail "references/ change without bump fails" "alpha: 1\.0\.0 -> 1\.0\.0" "$F"
+
+echo ""
+echo "--- 6. tests/-only change passes without bump ---"
+F="$(make_fixture)"
+mkdir -p "$F/plugins/demo/.apm/skills/alpha/tests"
+echo "t" > "$F/plugins/demo/.apm/skills/alpha/tests/test-x.sh"; commit "$F"
+expect_pass "tests/-only change is exempt" "$F"
+
+echo ""
+echo "--- 7. new skill exempt ---"
+F="$(make_fixture)"
+write_skill "$F" demo gamma 'version: "0.1.0"'; commit "$F"
+expect_pass "new skill passes" "$F"
+
+echo ""
+echo "--- 8. deleted skill exempt ---"
+F="$(make_fixture)"
+rm -rf "$F/plugins/demo/.apm/skills/alpha"; commit "$F"
+expect_pass "deleted skill passes" "$F"
+
+echo ""
+echo "--- 9. renamed skill exempt ---"
+F="$(make_fixture)"
+(cd "$F" && git mv plugins/demo/.apm/skills/alpha plugins/demo/.apm/skills/alpha2)
+commit "$F"
+expect_pass "renamed skill passes (old absent at pushed, new absent at baseline)" "$F"
+
+echo ""
+echo "--- 10. missing version on changed skill fails ---"
+F="$(make_fixture)"
+write_skill "$F" demo alpha "" "new body"; commit "$F"
+expect_fail "missing version fails" "alpha: metadata\.version missing" "$F"
+
+echo ""
+echo "--- 11. malformed / prerelease version fails ---"
+for v in 'version: 1.1' 'version: "1.0.1-rc1"'; do
+  F="$(make_fixture)"
+  write_skill "$F" demo alpha "$v" "new body"; commit "$F"
+  expect_fail "'$v' is rejected like skill-size-check rejects it" "alpha: metadata\.version missing or not" "$F"
+done
+
+echo ""
+echo "--- 12. multiple offenders all reported ---"
+F="$(make_fixture)"
+write_skill "$F" demo alpha 'version: "1.0.0"' "x"
+write_skill "$F" demo beta "version: 1.0.9" "x"
+commit "$F"
+OUT="$(run_check "$F" || true)"
+if grep -q "alpha: 1.0.0 -> 1.0.0" <<< "$OUT" && grep -q "beta: 1.0.9 -> 1.0.9" <<< "$OUT" \
+   && grep -q "bump PATCH at minimum" <<< "$OUT"; then
+  pass "both offenders and the fix are reported"
+else
+  fail "not every offender reported: $OUT"
+fi
+
+echo ""
+echo "--- 13. PRE_COMMIT_TO_REF respected over HEAD ---"
+F="$(make_fixture)"
+write_skill "$F" demo alpha 'version: "1.0.0"' "unbumped"; commit "$F"
+BAD="$(cd "$F" && git rev-parse HEAD)"
+(cd "$F" && git checkout -q -b clean main)
+expect_fail "unbumped TO_REF fails while HEAD is clean" "alpha: 1\.0\.0 -> 1\.0\.0" "$F" "$BAD"
+(cd "$F" && git checkout -q "$BAD")
+expect_pass "clean TO_REF passes while HEAD is unbumped" "$F" "$(cd "$F" && git rev-parse main)"
+
+echo ""
+echo "--- 14. all-zeros delete sha no-ops ---"
+F="$(make_fixture)"
+write_skill "$F" demo alpha 'version: "1.0.0"' "unbumped"; commit "$F"
+expect_pass "40-zero sha exits 0" "$F" "0000000000000000000000000000000000000000"
+expect_pass "64-zero sha exits 0" "$F" "$(printf '0%.0s' {1..64})"
+
+echo ""
+echo "--- 15. bin plugin covered ---"
+F="$(make_fixture)"
+write_skill "$F" bin tool 'version: "1.0.0"'
+(cd "$F" && git checkout -q main); commit "$F" "add bin skill"
+(cd "$F" && git checkout -q feature && git merge -q main)
+write_skill "$F" bin tool 'version: "1.0.0"' "changed"; commit "$F"
+expect_fail "bin skill change without bump fails" "plugins/bin/\.apm/skills/tool: 1\.0\.0 -> 1\.0\.0" "$F"
+
+echo ""
+echo "--- 16. multi-digit semver compare ---"
+F="$(make_fixture)"
+write_skill "$F" demo beta "version: 1.0.10" "x"; commit "$F"
+expect_pass "1.0.10 > 1.0.9 passes" "$F"
+
+echo ""
+echo "--- 17. baseline is the merge-base, not main's tip ---"
+F="$(make_fixture)"
+write_skill "$F" demo alpha 'version: "1.0.1"' "branch change"; commit "$F"
+(cd "$F" && git checkout -q main)
+write_skill "$F" demo alpha 'version: "1.0.5"' "main moved on"; commit "$F"
+(cd "$F" && git checkout -q feature)
+expect_pass "bump over the merge-base passes even though main is ahead" "$F"
+
+echo ""
+echo "--- 18. origin/main preferred over local main ---"
+F="$(make_fixture)"
+write_skill "$F" demo alpha 'version: "1.0.1"' "x"; commit "$F"
+# A stale local main pointing at the feature tip would make the diff empty;
+# origin/main at the original commit must win and still see the change.
+(cd "$F" && git update-ref refs/remotes/origin/main main && git branch -f main feature)
+write_skill "$F" demo alpha 'version: "1.0.1"' "y"; commit "$F"
+if OUT="$(run_check "$F")" && [[ -z "$OUT" ]]; then
+  pass "origin/main used as baseline (1.0.0 -> 1.0.1 counted as a bump)"
+else
+  fail "unexpected output: $OUT"
+fi
+(cd "$F" && git update-ref refs/remotes/origin/main feature~1)
+expect_fail "origin/main at the bumped commit flags the further unbumped change" \
+  "merge-base with origin/main" "$F"
+
+echo ""
+echo "--- 19. no main ref fails closed ---"
+F="$(mktemp -d)"; CLEANUP_DIRS+=("$F")
+(cd "$F" && git init -q -b trunk && git config user.email t@t.t && git config user.name t)
+write_skill "$F" demo alpha 'version: "1.0.0"'; commit "$F"
+expect_fail "missing main fails with a clear message" "neither origin/main nor main resolves" "$F"
+
+echo ""
+echo "Results: $PASS passed, $FAIL failed"
+[[ $FAIL -eq 0 ]]