Fix smoke test file permission error in Docker

Write report to sys_get_temp_dir() instead of tools/ directory,
and suppress with @ so it doesn't crash the page.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tools/smoke_test.php

@@ -461,8 +461,8 @@ if ($isCli) {
 }
 
 // ─── Save JSON report ───────────────────────────────────────────────────────
-$reportFile = __DIR__ . '/smoke_test_report.json';
-file_put_contents($reportFile, json_encode($results, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE));
+$reportFile = sys_get_temp_dir() . '/erp_smoke_test_report.json';
+@file_put_contents($reportFile, json_encode($results, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE));
 if ($isCli) output("Full report saved to: {$reportFile}");
 
 @unlink($cookieFile);