feat: add per-session agent sandbox

src/cli/gateway-cli.ts

@@ -33,7 +33,14 @@ type GatewayRunSignalAction = "stop" | "restart";
 
 function parsePort(raw: unknown): number | null {
   if (raw === undefined || raw === null) return null;
-  const parsed = Number.parseInt(String(raw), 10);
+  const value =
+    typeof raw === "string"
+      ? raw
+      : typeof raw === "number" || typeof raw === "bigint"
+        ? raw.toString()
+        : null;
+  if (value === null) return null;
+  const parsed = Number.parseInt(value, 10);
   if (!Number.isFinite(parsed) || parsed <= 0) return null;
   return parsed;
 }