fix(queue): preserve pending items during drains

src/agents/subagent-announce-queue.ts

@@ -162,7 +162,7 @@ function scheduleAnnounceDrain(key: string) {
             prompt,
             internalEvents: internalEvents.length > 0 ? internalEvents : last.internalEvents,
           });
-          queue.items.splice(0);
+          queue.items.splice(0, items.length);
           if (summary) {
             clearQueueSummaryState(queue);
           }

src/auto-reply/reply/queue/drain.ts

@@ -219,7 +219,7 @@ export function scheduleFollowupDrain(
               enqueuedAt: Date.now(),
               ...routing,
             });
-            queue.items.splice(0);
+            queue.items.splice(0, groupItems.length);
             if (pendingSummary) {
               clearQueueSummaryState(queue);
               pendingSummary = undefined;

src/infra/system-events.ts

@@ -167,7 +167,7 @@ export function consumeSystemEventEntries(
   ) {
     return [];
   }
-  const removed = entry.queue.splice(0).map(cloneSystemEvent);
+  const removed = entry.queue.splice(0, consumedEntries.length).map(cloneSystemEvent);
   if (entry.queue.length === 0) {
     entry.lastText = null;
     entry.lastContextKey = null;