retry capacity-style upstream errors

scripts/test-install-restore.mjs

@@ -221,6 +221,8 @@ async function run() {
       headers: { "content-type": "application/json" },
       body: JSON.stringify({
         reasoning_equals: [1024],
+        retryable_status_codes: [429, 503, 529],
+        retryable_error_messages: ["Selected model is at capacity. Please try a different model."],
         endpoints: ["/responses", "/v1/responses"],
         non_stream_status_code: 503,
         log_match: false,
@@ -237,6 +239,10 @@ async function run() {
       JSON.stringify(updatedGatewayConfig.reasoning_equals) === JSON.stringify([1024]),
       "Saved config file did not persist reasoning_equals",
     );
+    assert(
+      JSON.stringify(updatedGatewayConfig.retryable_status_codes) === JSON.stringify([429, 503, 529]),
+      "Saved config file did not persist retryable_status_codes",
+    );
 
     const incrementalLogsResponse = await fetch(
       `http://127.0.0.1:${gatewayPort}/__codex_retry_gateway/api/logs?since_seq=${logsPayload.latest_seq}`,