fix: reduce runner command poll latency

src/runner/k8s-job.ts

@@ -174,6 +174,7 @@ function runnerEnv(options: RunnerJobRenderOptions, context: { namespace: string
     { name: "AGENTRUN_K8S_JOB_NAME", value: context.jobName },
     { name: "AGENTRUN_LOG_PATH", value: "/tmp/agentrun-runner.jsonl" },
     { name: "AGENTRUN_RUNNER_IDLE_TIMEOUT_MS", value: "600000" },
+    { name: "AGENTRUN_RUNNER_POLL_INTERVAL_MS", value: "250" },
     { name: "HOME", value: "/home/agentrun" },
     { name: "CODEX_HOME", value: codexHome },
     ...(selectedSecret ? [{ name: "AGENTRUN_CODEX_SECRET_HOME", value: selectedSecret.projectionMountPath }] : []),

src/runner/run-once.ts

@@ -62,7 +62,7 @@ export async function runOnce(options: RunnerOnceOptions): Promise<JsonRecord> {
 
   const stopHeartbeat = startHeartbeat(api, options.runId, runner.id, leaseMs);
   const idleTimeoutMs = options.idleTimeoutMs ?? 120_000;
-  const pollIntervalMs = options.pollIntervalMs ?? 2_000;
+  const pollIntervalMs = normalizePollIntervalMs(options.pollIntervalMs);
   const commandResults: CommandExecutionResult[] = [];
   let workspacePath: string | undefined;
   let materializationAttempted = false;
@@ -231,3 +231,8 @@ function noPendingResult(runner: RunnerRecord, claimed: RunRecord, commandResult
 function sleep(ms: number): Promise<void> {
   return new Promise((resolve) => setTimeout(resolve, ms));
 }
+
+function normalizePollIntervalMs(value: number | undefined): number {
+  if (!Number.isFinite(value ?? NaN)) return 250;
+  return Math.max(50, Math.min(2_000, Math.floor(value!)));
+}