fix broken doc links

bin/codex-skills-sync.sh

@@ -50,6 +50,8 @@ target_dir="${codex_home_dir}/skills"
 managed_skills=(
   "core-guardrails"
   "starterkit-planner"
+  "starterkit-grid-standards"
+  "starterkit-php-style-ci"
 )
 
 for skill in "${managed_skills[@]}"; do
@@ -70,7 +72,7 @@ check_skill() {
   fi
 
   local diff
-  diff="$(rsync -rcn --delete --itemize-changes "${src}/" "${dst}/" || true)"
+  diff="$(diff -qr "${src}" "${dst}" || true)"
   if [[ -n "${diff}" ]]; then
     echo "[DRIFT] ${skill} differs:"
     echo "${diff}" | sed 's/^/  /'