Update upstream layout validation

tools/validate_upstream_layout.py

@@ -24,6 +24,9 @@ def main() -> int:
         "panel relay matcher": panel.count(
             r"r'(?m)^\s*reverse_proxy 127\.0\.0\.1:8080\s*\{'"
         ),
+        "panel credentials prompt": core.count(
+            'read -r -p "Panel administrator login [admin]: " PANEL_ADMIN'
+        ),
     }
 
     failed = False