fix(install): handle 'undefined' string from openclaw config get

- getJson now treats 'undefined' string as missing value
- Add try-catch to JSON.parse for robustness

scripts/install-dirigent-openclaw.mjs

@@ -67,8 +67,12 @@ function runOpenclaw(args, { allowFail = false } = {}) {
 
 function getJson(pathKey) {
   const out = runOpenclaw(["config", "get", pathKey, "--json"], { allowFail: true });
-  if (out == null || out === "") return undefined;
+  if (out == null || out === "" || out === "undefined") return undefined;
+  try {
     return JSON.parse(out);
+  } catch {
+    return undefined;
+  }
 }
 
 function setJson(pathKey, value) {