review: catch follow-up poll errors + re-check done before push

Two fixes on top of the follow-up pre-task-script work:

1. The void async IIFE inside the interval handler had no catch, so a
   throw from the dynamic import or applyPreTaskScripts escaped as an
   unhandled rejection — terminating the container. The initial-batch
   path is wrapped by processQuery's outer try/catch; the follow-up
   path needs its own. Now logs the error and lets the next tick retry.

2. Re-check `done` immediately before query.push. The flag can flip
   true while applyPreTaskScripts is awaited (outer stream finishes
   during the script execution); without the re-check we'd push into a
   closed query. Claimed messages get released by the host's
   processing-claim sweep — same recovery posture as the rest of the
   poller.

Co-Authored-By: Michael Zazon <mzazon@gmail.com>
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

container/agent-runner/src/poll-loop.ts

@@ -302,12 +302,23 @@ async function processQuery(
         // MODULE-HOOK:scheduling-pre-task-followup:end
 
         if (keep.length === 0) return;
+        // Re-check done — the outer query may have finished while the script
+        // was awaited. Pushing into a closed stream is wasted work; the
+        // claimed messages get released by the host's processing-claim sweep.
+        if (done) return;
 
         const keptIds = keep.map((m) => m.id);
         const prompt = formatMessages(keep);
         log(`Pushing ${keep.length} follow-up message(s) into active query`);
         query.push(prompt);
         markCompleted(keptIds);
+      } catch (err) {
+        // Without this catch the rejection escapes the void IIFE and Node
+        // terminates the container on unhandled-rejection. The initial-batch
+        // path is wrapped by processQuery's outer try/catch; the follow-up
+        // path is not, so it needs its own.
+        const errMsg = err instanceof Error ? err.message : String(err);
+        log(`Follow-up poll error: ${errMsg}`);
       } finally {
         pollInFlight = false;
       }