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.

lib/tests/profile-default.test.sh

@@ -18,7 +18,8 @@ check_not() { case "$2" in *"$3"*) fail=$((fail+1));
 
 FX="$(mktemp -d)"; trap 'rm -rf "$FX"' EXIT
 mkdir -p "$FX/skills" "$FX/skills-disabled" "$FX/lib/profiles" "$FX/bin" \
-  "$FX/hooks" "$FX/skills-external/emil-design-eng"
+  "$FX/hooks" "$FX/skills-external/emil-design-eng" \
+  "$FX/skills-external/observability-and-instrumentation"
 for g in gs-a gs-b gs-c; do
   mkdir -p "$FX/skills-external/gstack/$g"
   touch "$FX/skills-external/gstack/$g/SKILL.md"
@@ -29,7 +30,8 @@ cp "$ROOT/hooks/statusline.sh" "$FX/hooks/"
 cat > "$FX/lib/profiles/full.profile" <<'EOF'
 gs-a
 gs-b
-emil-design-eng   external
+emil-design-eng                     external
+observability-and-instrumentation   external
 EOF
 cat > "$FX/lib/profiles/otherish.profile" <<'EOF'
 gs-c
@@ -89,6 +91,7 @@ check T5-gsa-on  "$([ -e "$FX/skills/gs-a" ] && echo on || echo off)" on
 check T5-gsb-on  "$([ -e "$FX/skills/gs-b" ] && echo on || echo off)" on
 check T5-gsc-off "$([ -e "$FX/skills/gs-c" ] && echo on || echo off)" off
 check T5-emil-on "$([ -e "$FX/skills/emil-design-eng" ] && echo on || echo off)" on
+check T5-obs-on  "$([ -e "$FX/skills/observability-and-instrumentation" ] && echo on || echo off)" on
 out="$(run current)"
 check     T5-first-word  "$(first_word "$out")" full
 check_has T5-match        "$out" "100% match"

lib/tests/profile-set-managed.test.sh

@@ -13,7 +13,8 @@ check() { if [ "$2" = "$3" ]; then pass=$((pass+1)); else fail=$((fail+1));
 FX="$(mktemp -d)"; trap 'rm -rf "$FX"' EXIT
 mkdir -p "$FX/skills" "$FX/skills-disabled" "$FX/lib/profiles" "$FX/bin" \
   "$FX/skills-external/emil-design-eng" "$FX/skills-external/other-ext" \
-  "$FX/skills-external/21st-ui-build"
+  "$FX/skills-external/21st-ui-build" \
+  "$FX/skills-external/observability-and-instrumentation"
 for g in gs-a gs-b gs-c; do
   mkdir -p "$FX/skills-external/gstack/$g"
   touch "$FX/skills-external/gstack/$g/SKILL.md"
@@ -26,8 +27,9 @@ ln -s "$FX/skills-external/other-ext" "$FX/skills/other-ext"
 cat > "$FX/lib/profiles/designish.profile" <<'EOF'
 gs-a
 gs-b
-emil-design-eng   external
-21st-ui-build     external
+emil-design-eng                     external
+21st-ui-build                       external
+observability-and-instrumentation   external
 EOF
 cat > "$FX/lib/profiles/backendish.profile" <<'EOF'
 gs-c
@@ -53,6 +55,7 @@ check T2-gsb-on   "$([ -e "$FX/skills/gs-b" ] && echo on || echo off)" on
 check T3-gsc-off  "$([ -e "$FX/skills/gs-c" ] && echo on || echo off)" off
 check T4-emil-src "$([ -L "$FX/skills/emil-design-eng" ] && echo on || echo off)" on
 check T5-21st-src "$([ -L "$FX/skills/21st-ui-build" ] && echo on || echo off)" on
+check T5b-obs-src "$([ -L "$FX/skills/observability-and-instrumentation" ] && echo on || echo off)" on
 check T6-no-mcp   "$(grep -c '^mcp ' "$FX/claude-calls.log" || true)" 0
 
 # --- set backendish: managed leftovers parked/unregistered ---
@@ -63,6 +66,8 @@ check T9-emil-off  "$([ -e "$FX/skills/emil-design-eng" ] && echo on || echo off
 check T10-emil-park "$([ -e "$FX/skills-disabled/emil-design-eng" ] && echo p || echo n)" p
 check T11-21st-off "$([ -e "$FX/skills/21st-ui-build" ] && echo on || echo off)" off
 check T12-21st-park "$([ -e "$FX/skills-disabled/21st-ui-build" ] && echo p || echo n)" p
+check T12b-obs-off  "$([ -e "$FX/skills/observability-and-instrumentation" ] && echo on || echo off)" off
+check T12c-obs-park "$([ -e "$FX/skills-disabled/observability-and-instrumentation" ] && echo p || echo n)" p
 check T13-other-untouched "$([ -e "$FX/skills/other-ext" ] && echo on || echo off)" on
 
 # --- back to designish: parked external restored (not re-sourced) ---
@@ -70,6 +75,8 @@ run set designish >/dev/null 2>&1
 check T14-emil-back "$([ -e "$FX/skills/emil-design-eng" ] && echo on || echo off)" on
 check T15-park-gone "$([ -e "$FX/skills-disabled/emil-design-eng" ] && echo p || echo n)" n
 check T16-21st-back "$([ -e "$FX/skills/21st-ui-build" ] && echo on || echo off)" on
+check T16b-obs-back "$([ -e "$FX/skills/observability-and-instrumentation" ] && echo on || echo off)" on
+check T16c-obs-park-gone "$([ -e "$FX/skills-disabled/observability-and-instrumentation" ] && echo p || echo n)" n
 check T17-no-mcp-ever "$(grep -c '^mcp ' "$FX/claude-calls.log" || true)" 0
 
 printf 'PASS=%s FAIL=%s\n' "$pass" "$fail"; [ "$fail" -eq 0 ]

lib/tests/toggle-external-repo-resolution.test.sh

@@ -14,6 +14,7 @@ check() { if [ "$2" = "$3" ]; then pass=$((pass+1)); else fail=$((fail+1));
 
 SANDBOX="$(mktemp -d)"
 mkdir -p "$SANDBOX/repo/lib" "$SANDBOX/repo/skills-external/emil-design-eng" \
+  "$SANDBOX/repo/skills-external/observability-and-instrumentation" \
   "$SANDBOX/repo/skills" "$SANDBOX/home/.claude"
 cp "$HELPER_SRC" "$SANDBOX/repo/lib/toggle-external.sh"
 # mark emil-design-eng ENABLED in the real (physical) repo tree
@@ -24,5 +25,11 @@ ln -s "$SANDBOX/repo/lib" "$SANDBOX/home/.claude/lib"
 out="$(bash "$SANDBOX/home/.claude/lib/toggle-external.sh" status emil-design-eng)"
 check T1-repo-resolves-through-symlink "$out" enabled
 
+# Same case arm, generalized to $tool for the agent-skills trio (this PR) —
+# left unlinked, so it must resolve through the symlink as "disabled", not
+# "missing" (which would mean REPO fell back to the wrong tree again).
+out="$(bash "$SANDBOX/home/.claude/lib/toggle-external.sh" status observability-and-instrumentation)"
+check T2-generalized-tool-resolves-through-symlink "$out" disabled
+
 rm -rf "$SANDBOX"
 printf 'PASS=%s FAIL=%s\n' "$pass" "$fail"; [ "$fail" -eq 0 ]