detect: set process.exitCode instead of exiting after the final write

process.exit() right after a large piped stdout write truncated JSON output
at the pipe buffer boundary; found by the oracle harness. Re-record the six
directory-scan goldens that had captured the truncation.

Prepared with AI assistance (Claude Code).

cli/engine/cli/main.mjs

@@ -423,10 +423,14 @@ async function detectCli() {
       }
     }
     else process.stderr.write(formatFindings(allFindings, false) + '\n');
-    process.exit(primary.length > 0 ? 2 : 0);
+    // Set the exit code instead of calling process.exit(): a piped stdout is
+    // written asynchronously, and exiting right after a large write truncates
+    // the JSON at the pipe buffer boundary (~64 KiB).
+    process.exitCode = primary.length > 0 ? 2 : 0;
+    return;
   }
   if (jsonMode) process.stdout.write('[]\n');
-  process.exit(0);
+  process.exitCode = 0;
 }
 
 export { formatFindings, handleStdin, confirm, printUsage, detectCli };