diff --git a/scripts/check-naming-and-style.sh b/scripts/check-naming-and-style.sh
index 7cadfba..bf0cf42 100755
--- a/scripts/check-naming-and-style.sh
+++ b/scripts/check-naming-and-style.sh
@@ -106,6 +106,23 @@ if [ -n "$SNAKE_FE" ]; then
     VIOLATIONS=$((VIOLATIONS + 1))
 fi
 
+# ADR-013 Phase 4: a plugin frontend (plugins/<name>/frontend/) may import core
+# via the @/ alias or its own tree (./, ../ within the plugin), never another
+# plugin's tree and never an escaping ../../ into src. Keeps plugin frontends
+# self-contained so a per-site build can drop one cleanly.
+echo "==> Checking for cross-plugin / escaping imports in plugin frontends..."
+if [ -d plugins ]; then
+    PLUGIN_FE_IMPORTS=$(grep -rPn "(import|from)\s+['\"]([^'\"]*\.\./\.\./|[^'\"]*/plugins/)" \
+        --include='*.vue' --include='*.js' plugins/*/frontend/ 2>/dev/null || true)
+    if [ -n "$PLUGIN_FE_IMPORTS" ]; then
+        echo "FAIL: plugin frontend imports must use the @/ alias for core, not"
+        echo "      an escaping ../../ or another plugin's path:"
+        echo "$PLUGIN_FE_IMPORTS"
+        echo
+        VIOLATIONS=$((VIOLATIONS + 1))
+    fi
+fi
+
 if [ "$VIOLATIONS" -gt 0 ]; then
     echo "=================================================="
     echo "$VIOLATIONS naming/style violation(s) found."