fix: don't delete job when returning state-mismatch error to keep UI in sync

When waitForJobCompletion threw and the job was still not terminal, we
were returning an error but still deleting the job in the finally block.
This left the UI holding an error while the job (still alive) would be
cleaned up by Kubernetes, causing the next heartbeat to find nothing and
think it was safe to retry — spawning a concurrent pod.

Now we set skipCleanup=true when returning the mismatch error, so the
job is retained and the heartbeat can still find and wait on it.

Also removes a duplicate empty-stdout fallback block.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/server/execute.ts

@@ -379,6 +379,9 @@ export async function execute(ctx: AdapterExecutionContext): Promise<AdapterExec
   let exitCode: number | null = null;
   let jobTimedOut = false;
   let keepaliveTimer: ReturnType<typeof setInterval> | null = null;
+  // Set when we return a mismatch error so the finally block knows not to
+  // delete a job that is still alive and the UI is waiting on.
+  let skipCleanup = false;
 
   try {
     // Wait for pod to be ready for log streaming
@@ -444,16 +447,6 @@ export async function execute(ctx: AdapterExecutionContext): Promise<AdapterExec
       }
     }
 
-    // If the follow stream missed output (container exited quickly), do a
-    // one-shot log read as fallback before the pod is cleaned up.
-    if (!stdout.trim()) {
-      await onLog("stdout", `[paperclip] Log stream returned empty — reading pod logs directly...\n`);
-      stdout = await readPodLogs(namespace, podName, kubeconfigPath);
-      if (stdout.trim()) {
-        await onLog("stdout", stdout);
-      }
-    }
-
     if (completionResult.status === "fulfilled") {
       jobTimedOut = completionResult.value.timedOut;
     } else {
@@ -470,6 +463,7 @@ export async function execute(ctx: AdapterExecutionContext): Promise<AdapterExec
         // Return an error so the UI knows the run is not done, rather than
         // returning with parsed (potentially incomplete) stdout.
         await onLog("stderr", `[paperclip] Job ${jobName} still not terminal after log/completion mismatch — returning error to keep UI in sync.\n`);
+        skipCleanup = true;
         return {
           exitCode,
           signal: null,
@@ -483,7 +477,9 @@ export async function execute(ctx: AdapterExecutionContext): Promise<AdapterExec
     exitCode = await getPodExitCode(namespace, jobName, kubeconfigPath);
   } finally {
     if (keepaliveTimer) clearInterval(keepaliveTimer);
-    if (!retainJobs) {
+    if (skipCleanup) {
+      await onLog("stdout", `[paperclip] Retaining job ${jobName} (state mismatch — UI is waiting on it)\n`);
+    } else if (!retainJobs) {
       await cleanupJob(namespace, jobName, onLog, kubeconfigPath);
     } else {
       await onLog("stdout", `[paperclip] Retaining job ${jobName} for debugging (retainJobs=true)\n`);