chore(deps): update agent skills (plugins/agentic-engineering/skills/product-engineering)

.claude-plugin/marketplace.json

@@ -27,7 +27,7 @@
     {
       "name": "agentic-engineering",
       "description": "The autonomous engineering system for repository portfolios — engineer, read-only surveyor, and meta-engineer agents; portfolio, product, spend, and improvement workflows; cross-tool instruction architecture and skill discovery; configured by the consumer AGENTS.md",
-      "version": "6.1.11",
+      "version": "6.1.12",
       "source": "./plugins/agentic-engineering"
     },
     {

.github/plugin/marketplace.json

@@ -27,7 +27,7 @@
     {
       "name": "agentic-engineering",
       "description": "The autonomous engineering system for repository portfolios — engineer, read-only surveyor, and meta-engineer agents; portfolio, product, spend, and improvement workflows; cross-tool instruction architecture and skill discovery; configured by the consumer AGENTS.md",
-      "version": "6.1.11",
+      "version": "6.1.12",
       "source": "./plugins/agentic-engineering"
     },
     {

plugins/agentic-engineering/.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "agentic-engineering",
   "description": "The autonomous engineering system for repository portfolios — engineer, read-only surveyor, and meta-engineer agents; portfolio, product, spend, and improvement workflows; cross-tool instruction architecture and skill discovery; configured by the consumer AGENTS.md",
-  "version": "6.1.11",
+  "version": "6.1.12",
   "author": {
     "name": "devantler-tech",
     "url": "https://github.com/devantler-tech"

plugins/agentic-engineering/CHANGELOG.md

@@ -21,6 +21,10 @@ The format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/) and
 new one before re-enabling unattended writes. Stopping early resumes writes with the retired FinOps
 schedule still armed, or with a schedule pointing at an entrypoint that no longer resolves.
 
+## 6.1.12 — 2026-10-05
+
+**Changed** — sync `product-engineering` from `https://github.com/devantler-tech/agent-skills` at `refs/tags/v1.21.31`.
+
 ## 6.1.11 — 2026-10-05
 
 **Changed** — sync `agent-improvement` from `https://github.com/devantler-tech/agent-skills` at `refs/tags/v1.21.29`.

plugins/agentic-engineering/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "agentic-engineering",
   "description": "The autonomous engineering system for repository portfolios — engineer, read-only surveyor, and meta-engineer agents; portfolio, product, spend, and improvement workflows; cross-tool instruction architecture and skill discovery; configured by the consumer AGENTS.md",
-  "version": "6.1.11",
+  "version": "6.1.12",
   "author": {
     "name": "devantler-tech",
     "url": "https://github.com/devantler-tech"

plugins/agentic-engineering/skills/product-engineering/SKILL.md

@@ -3,9 +3,9 @@ description: 'The ADVANCE playbook for an autonomous AI engineer — how to move
 license: Apache-2.0
 metadata:
     github-path: product-engineering
-    github-ref: refs/tags/v1.21.27
+    github-ref: refs/tags/v1.21.31
     github-repo: https://github.com/devantler-tech/agent-skills
-    github-tree-sha: 32ad063f85e506accbcd1ec661aabb8263f58af3
+    github-tree-sha: 3f214543fb26f041a047f0843e88ade53f2e91cd
 name: product-engineering
 ---
 # Product engineering — moving products forward

plugins/agentic-engineering/skills/product-engineering/references/tool-maturation.md

@@ -45,9 +45,13 @@ working tree is dirty, without checking out or executing its files. Its conserva
 `tracked-shell-paths-v1` includes every tracked regular `*.sh` path except `*.test.sh`; it does not
 apply a size threshold or decide which files are non-trivial. Each path carries its committed blob
 identifier and executable bit. Before selecting files, it compares the complete tree listing with
-an independent raw diff from Git's empty tree to the named commit. Missing complete records,
+an independent raw diff from Git's empty tree to the named commit. Each reachable tree object's
+original bytes must also pass Git's canonical component validation and retain their committed
+identity; agreement between flattened paths alone cannot establish a valid tree. Missing complete records,
 disagreement between those views, tree/object read failures, selected symlinks and paths that cannot
 be represented faithfully in UTF-8 JSON produce exit `2` (`UNKNOWN`) with no success payload.
+Git observations also suppress configured filesystem-monitor callbacks without changing repository
+configuration, so a native tree read cannot silently execute a caller-provided hook.
 
 To include Go entrypoint evidence, add `--include-go` to the same invocation. This opt-in needs
 Go 1.22 or later and compiles only the installed `scripts/go-entrypoint.go` parser, with modules,

plugins/agentic-engineering/skills/product-engineering/scripts/inspect-shell-helpers.sh

@@ -43,7 +43,7 @@ export GIT_NO_LAZY_FETCH=1
 unset GIT_DIR GIT_WORK_TREE GIT_COMMON_DIR GIT_INDEX_FILE GIT_OBJECT_DIRECTORY \
   GIT_ALTERNATE_OBJECT_DIRECTORIES GIT_NAMESPACE
 # Explicit no-fetch capability is required; unsupported Git refuses before reads.
-read_git() { git --no-lazy-fetch --no-replace-objects --no-optional-locks -C "$repo" "$@"; }
+read_git() { git -c core.fsmonitor=false --no-lazy-fetch --no-replace-objects --no-optional-locks -C "$repo" "$@"; }
 top=$(read_git rev-parse --show-toplevel 2>/dev/null && printf '.') || unknown 'not a worktree repository'
 top=${top%$'\n.'}
 top=$(cd "$top" && pwd -P && printf '.') || unknown 'repository root is unavailable'
@@ -69,6 +69,9 @@ read_git diff-tree -r -t --raw -z --no-abbrev --no-commit-id --no-renames \
 encode_record() { printf '%s %s\t%s\0' "$1" "$2" "$3" | base64 | tr -d '\r\n' || return; printf '\n'; }
 : > "$tmp/tree-records"
 : > "$tmp/tree-paths"
+root_tree=$(read_git rev-parse --verify "$revision^{tree}" 2>/dev/null) || unknown 'root tree identity is unavailable'
+[[ $root_tree =~ ^([0-9a-f]{40}|[0-9a-f]{64})$ ]] || unknown 'root tree identity is invalid'
+printf '%s\n' "$root_tree" > "$tmp/tree-objects"
 entry=
 while IFS= read -r -d '' entry; do
   [[ $entry == *$'\t'* ]] || unknown 'malformed tree entry'
@@ -80,10 +83,20 @@ while IFS= read -r -d '' entry; do
     040000:tree|100644:blob|100755:blob|120000:blob|160000:commit) : ;;
     *) unknown 'unsupported tree metadata' ;;
   esac
+  [[ $type != tree ]] || printf '%s\n' "$blob" >> "$tmp/tree-objects"
   encode_record "$mode" "$blob" "$path" >> "$tmp/tree-records" || unknown 'tree record could not be encoded'
   encode_record '' '' "$path" >> "$tmp/tree-paths" || unknown 'tree path could not be encoded'
 done < "$tmp/tree"
 [[ -z $entry ]] || unknown 'committed tree has an unterminated record'
+# Flattened listings cannot distinguish nested paths from malformed tree components.
+# Git parses each original tree without writing objects; bind the complete raw read
+# back to its immutable identity before accepting any inventory.
+LC_ALL=C sort -u "$tmp/tree-objects" > "$tmp/unique-tree-objects" || unknown 'tree objects could not be compared'
+while IFS= read -r tree_object; do
+  read_git cat-file tree "$tree_object" > "$tmp/raw-tree" 2>/dev/null || unknown 'original tree object could not be read'
+  observed_tree=$(read_git hash-object -t tree --stdin < "$tmp/raw-tree" 2>/dev/null) || unknown 'original tree components are not canonical'
+  [[ $observed_tree == "$tree_object" ]] || unknown 'original tree bytes do not match the committed identity'
+done < "$tmp/unique-tree-objects"
 : > "$tmp/diff-records"
 header=
 while IFS= read -r -d '' header; do

plugins/agentic-engineering/skills/product-engineering/scripts/inspect-shell-observation.test.sh

@@ -0,0 +1,44 @@
+#!/usr/bin/env bash
+# Configured observation callbacks must stay inert, including at valid trees.
+set -euo pipefail
+unset GIT_DIR GIT_WORK_TREE GIT_COMMON_DIR GIT_INDEX_FILE GIT_OBJECT_DIRECTORY \
+  GIT_ALTERNATE_OBJECT_DIRECTORIES GIT_NAMESPACE GIT_PREFIX
+here=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+work=$(mktemp -d)
+trap 'rm -rf "$work"' EXIT
+git init -q "$work/repo"
+git -C "$work/repo" config user.name 'Observation fixture'
+git -C "$work/repo" config user.email fixture@example.invalid
+printf '#!/bin/sh\nexit 0\n' > "$work/repo/helper.sh"
+git -C "$work/repo" add helper.sh
+git -C "$work/repo" -c commit.gpgsign=false commit -qm fixture
+revision=$(git -C "$work/repo" rev-parse HEAD)
+printf '#!/bin/sh\nprintf executed > "%s"\nprintf "token\\n"\n' "$work/marker" > "$work/hook"
+chmod +x "$work/hook"
+git -C "$work/repo" config core.fsmonitor "$work/hook"
+# Snapshot raw caller files, without an index-consulting observation of our own.
+snapshot() {
+  shasum "$work/repo/.git/index" "$work/repo/.git/config"
+  find "$work/repo/.git/refs" "$work/repo/.git/objects" -type f -exec shasum {} + | LC_ALL=C sort
+}
+snapshot > "$work/before"
+pass=0 fail=0
+record() {
+  if "$@"; then printf 'PASS: %s\n' "$label"; pass=$((pass+1))
+  else printf 'FAIL: %s\n' "$label"; fail=$((fail+1)); fi
+}
+bash "$here/inspect-shell-helpers.sh" --repo-dir "$work/repo" --revision "$revision" > "$work/disabled"
+label='disabled inventory retains no execution authority'
+record jq -e '.status=="DISABLED" and .authority=="NONE"' "$work/disabled"
+label='disabled inventory never runs the configured hook'; record test ! -e "$work/marker"
+bash "$here/inspect-shell-helpers.sh" --inspect --repo-dir "$work/repo" --revision "$revision" > "$work/enabled"
+label='enabled inventory retains its exact committed helper'
+record jq -e '.status=="OBSERVED" and .authority=="NONE" and .coverage.selectedPaths==1 and .candidates[0].path=="helper.sh"' "$work/enabled"
+label='enabled inventory never runs the configured hook'; record test ! -e "$work/marker"
+snapshot > "$work/after"
+label='observations retain index, configuration, refs and objects'; record cmp "$work/before" "$work/after"
+# The harmless callback is executable and its marker would detect execution.
+"$work/hook" > "$work/control"
+label='configured marker callback is an effective control'; record test -s "$work/marker"
+printf 'Observation controls: %s pass, %s fail\n' "$pass" "$fail"
+[[ $fail == 0 ]]

plugins/agentic-engineering/skills/product-engineering/scripts/inspect-shell-tree-integrity.test.sh

@@ -0,0 +1,82 @@
+#!/usr/bin/env bash
+# Canonical tree components must be observed before flattened paths can prove coverage.
+set -euo pipefail
+unset GIT_DIR GIT_WORK_TREE GIT_COMMON_DIR GIT_INDEX_FILE GIT_OBJECT_DIRECTORY \
+  GIT_ALTERNATE_OBJECT_DIRECTORIES GIT_NAMESPACE GIT_PREFIX
+here=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+work=$(mktemp -d)
+trap 'rm -rf "$work"' EXIT
+pass=0 fail=0
+# Preserve all results so malformed and valid controls run against the same object store.
+record() {
+  if "$@"; then printf 'PASS: %s\n' "$label"; pass=$((pass + 1))
+  else printf 'FAIL: %s\n' "$label"; fail=$((fail + 1)); fi
+}
+git init -q "$work/repo"
+git -C "$work/repo" config user.name 'Tree integrity fixture'
+git -C "$work/repo" config user.email fixture@example.invalid
+git -C "$work/repo" config commit.gpgsign false
+blob=$(printf 'do not execute\n' | git -C "$work/repo" hash-object -w --stdin)
+# Write Git's binary tree representation directly; mktree refuses malformed components.
+raw_tree() {
+  local mode=$1 name=$2 object=$3 i
+  printf '%s %s\0' "$mode" "$name"
+  for ((i=0; i<${#object}; i+=2)); do printf '%b' "\\x${object:i:2}"; done
+}
+# Invoke the real installed observer and retain both streams and the native exit code.
+observe() {
+  status=0
+  bash "$here/inspect-shell-helpers.sh" --inspect --repo-dir "$work/repo" \
+    --revision "$1" > "$work/out" 2> "$work/error" || status=$?
+}
+# UNKNOWN must never carry a partial success report.
+refused() { [[ $status == 2 && ! -s $work/out ]] && grep -q '^UNKNOWN:' "$work/error"; }
+# A nested path remains legitimate even though its flattened spelling contains a slash.
+raw_tree 100644 $'quoted" tab\tline\n.sh' "$blob" > "$work/nested.tree"
+nested=$(git -C "$work/repo" hash-object -t tree -w "$work/nested.tree")
+printf '040000 tree %s\tfolder\0' "$nested" | git -C "$work/repo" mktree -z > "$work/root"
+root=$(cat "$work/root")
+valid=$(printf 'valid nested fixture\n' | git -C "$work/repo" commit-tree "$root")
+observe "$valid"
+label='nested whitespace path retains exact committed identity'
+# shellcheck disable=SC2016 # These variables belong to jq.
+record jq -e --arg path $'folder/quoted" tab\tline\n.sh' --arg blob "$blob" \
+  '.status=="OBSERVED" and .coverage.selectedPaths==1 and .candidates[0].path==$path and .candidates[0].blob==$blob' "$work/out"
+
+for name in ../escape.sh folder/slashed.sh . .. .git; do
+  raw_tree 100644 "$name" "$blob" > "$work/raw.tree"
+  tree=$(git -C "$work/repo" hash-object --literally -t tree -w "$work/raw.tree")
+  revision=$(printf 'malformed component fixture\n' | git -C "$work/repo" commit-tree "$tree")
+  observe "$revision"
+  label="malformed component refuses: $name"
+  record refused
+  # Every reachable subtree needs validation, including nonselected components.
+  printf '040000 tree %s\tnested\0' "$tree" | git -C "$work/repo" mktree -z > "$work/nested-root"
+  revision=$(printf 'nested malformed fixture\n' | git -C "$work/repo" commit-tree "$(cat "$work/nested-root")")
+  observe "$revision"
+  label="nested malformed component refuses: $name"
+  record refused
+done
+observe "$valid"
+label='unrelated malformed objects do not invalidate the selected valid tree'
+record jq -e '.status=="OBSERVED" and .coverage.selectedPaths==1' "$work/out"
+
+# Failed and substituted raw-object reads cannot masquerade as complete tree inspection.
+real_git=$(command -v git)
+mkdir "$work/bin"
+cat > "$work/bin/git" <<'STUB'
+#!/usr/bin/env bash
+if [[ " $* " == *' cat-file tree '* ]]; then
+  if [[ $MODE == partial ]]; then "$REAL_GIT" "$@"; exit 73; fi
+  exit 0
+fi
+exec "$REAL_GIT" "$@"
+STUB
+chmod +x "$work/bin/git"
+for mode in partial substituted; do
+  MODE=$mode REAL_GIT=$real_git PATH="$work/bin:$PATH" observe "$valid"
+  label="$mode raw-tree read refuses without success"
+  record refused
+done
+printf 'Tree integrity controls: %s pass, %s fail\n' "$pass" "$fail"
+[[ $fail == 0 ]]