feat(skills): vendor agent-skills trio at a pinned commit, emil precedent

observability-and-instrumentation, deprecation-and-migration,
ci-cd-and-automation from addyosmani/agent-skills 2686b620, curl'd into
skills-external/<name>/ by install-plugins.sh Step 8e (tmp+mv), refreshed
by update-all.sh 7.3, symlinked by link.sh, registered in toggle-external,
profile.sh and the full/backend/dev profiles. Pin read from the lock via
argv, never hardcoded. Case 2 of the 6-repo review, BDR-102.

install-plugins.sh

@@ -90,6 +90,22 @@ print(v)
   fi
 }
 
+# Read a pinned commit sha from plugins.lock.json (agent-skills style entries
+# — no "version", a "commit" field instead). Prints the sha, or "" if the
+# entry or the field is absent.
+# Usage: pinned_commit "agent-skills" → prints the commit sha or ""
+pinned_commit() {
+  local key="$1"
+  if [ -f "$REPO/plugins.lock.json" ] && command -v python3 &>/dev/null; then
+    python3 -c "
+import json, sys
+with open(sys.argv[1]) as f:
+    d = json.load(f)
+print(d.get(sys.argv[2], {}).get('commit', ''))
+" "$REPO/plugins.lock.json" "$key" 2>/dev/null || true
+  fi
+}
+
 # ============================================================
 # DETECT OS
 # ============================================================
@@ -899,6 +915,43 @@ else
 fi
 echo ""
 
+# ── Step 8e: Agent Skills (addyosmani/agent-skills, pinned commit) ──
+# Three dev-lifecycle skills vendored the emil-design-eng way (curl →
+# skills-external/<name>/SKILL.md, symlinked by link.sh) but COMMIT-pinned
+# instead of tracking main: the sha lives in plugins.lock.json ("agent-skills"
+# entry), never hardcoded here.
+echo "── Step 8e: Agent Skills (addyosmani/agent-skills) ─────────"
+echo ""
+AGENT_SKILLS_NAMES=(observability-and-instrumentation deprecation-and-migration ci-cd-and-automation)
+AGENT_SKILLS_SHA=$(pinned_commit "agent-skills")
+if [ -z "$AGENT_SKILLS_SHA" ]; then
+  err "agent-skills: no commit pinned in plugins.lock.json — add an \"agent-skills\" entry with a \"commit\" field"
+else
+  for _as_skill in "${AGENT_SKILLS_NAMES[@]}"; do
+    _as_dir="$REPO/skills-external/$_as_skill"
+    _as_url="https://raw.githubusercontent.com/addyosmani/agent-skills/$AGENT_SKILLS_SHA/skills/$_as_skill/SKILL.md"
+    mkdir -p "$_as_dir"
+    if [ -f "$_as_dir/SKILL.md" ]; then
+      ok "$_as_skill already downloaded"
+    else
+      info "Downloading SKILL.md from addyosmani/agent-skills ($_as_skill)..."
+      if curl -fsSL "$_as_url" -o "$_as_dir/SKILL.md.tmp" \
+        && mv "$_as_dir/SKILL.md.tmp" "$_as_dir/SKILL.md"; then
+        ok "$_as_skill installed"
+      else
+        rm -f "$_as_dir/SKILL.md.tmp"
+        err "$_as_skill download failed — try: curl -fsSL $_as_url -o $_as_dir/SKILL.md"
+      fi
+    fi
+    if [ -L "$HOME/.claude/skills/$_as_skill" ]; then
+      ok "$_as_skill symlink OK"
+    else
+      info "Symlinking $_as_skill — will be created by link.sh"
+    fi
+  done
+fi
+echo ""
+
 # ============================================================
 # STEP 8.5 — EXTERNAL SKILLS (npx skills add …)
 # ============================================================
@@ -1186,6 +1239,7 @@ echo "    🔄 emil-design-eng     — UI polish, animations, component craft (c
 echo "    🔄 frontend-design     — distinctive frontend interfaces, anti-AI-slop (anthropic-agent-skills)"
 echo "    🔄 impeccable          — /impeccable design verbs + 45-rule deterministic detector (npx impeccable detect)"
 echo "    🔄 design-motion-principles — motion/animation design, 3-designer lens (kylezantos)"
+echo "    🔄 agent-skills trio   — observability-and-instrumentation, deprecation-and-migration, ci-cd-and-automation (curl → symlink, pinned commit)"
 echo "    🔄 darwin-skill        — autonomous skill optimizer (npx skills, ~/.agents/skills/)"
 echo "    🔄 21st skill pack     — 21st.dev CLI skills; design ones follow the profile (full by default), publishing ones on demand (toggle: lib/toggle-external.sh enable 21st)"
 echo ""
@@ -1194,6 +1248,7 @@ echo "  GStack skills symlinked individually into ~/.claude/skills/ (→ submodu
 echo "  Emil Design Eng at: ~/.claude/skills/emil-design-eng/ (symlink → skills-external)"
 echo "  Frontend Design at: ~/.claude/skills/frontend-design/ (symlink → skills-external)"
 echo "  Design Motion Principles at: ~/.claude/skills/design-motion-principles/ (symlink → skills-external)"
+echo "  Agent Skills trio at: ~/.claude/skills/{observability-and-instrumentation,deprecation-and-migration,ci-cd-and-automation}/ (symlink → skills-external)"
 echo "  npx skills at: ~/.agents/skills/ (symlinked into ~/.claude/skills/)"
 echo ""
 echo "  → Restart Claude Code — plugins load automatically"