fix: correctly trigger idle preemption in streaming input mode

The original notifyIdle condition (!result.result) never fired in
streaming input mode because every result has non-null text content.
This caused due tasks to wait up to 30 minutes for the idle timer.

- Call notifyIdle for ALL successful results (not just null ones)
- Add isTaskContainer flag so user messages queue instead of being
  forwarded to task containers (which blocked notifyIdle from the
  message container's onOutput path)
- Reset idleWaiting in sendMessage so containers aren't preempted
  while actively working on a new incoming message
- Replace 30-min IDLE_TIMEOUT with 10s close timer for task containers
  since they are single-turn and should exit promptly after their result

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

src/task-scheduler.ts

@@ -89,16 +89,18 @@ async function runTask(
   const sessionId =
     task.context_mode === 'group' ? sessions[task.group_folder] : undefined;
 
-  // Idle timer: writes _close sentinel after IDLE_TIMEOUT of no output,
-  // so the container exits instead of hanging at waitForIpcMessage forever.
-  let idleTimer: ReturnType<typeof setTimeout> | null = null;
+  // After the task produces a result, close the container promptly.
+  // Tasks are single-turn — no need to wait IDLE_TIMEOUT (30 min) for the
+  // query loop to time out. A short delay handles any final MCP calls.
+  const TASK_CLOSE_DELAY_MS = 10000;
+  let closeTimer: ReturnType<typeof setTimeout> | null = null;
 
-  const resetIdleTimer = () => {
-    if (idleTimer) clearTimeout(idleTimer);
-    idleTimer = setTimeout(() => {
-      logger.debug({ taskId: task.id }, 'Scheduled task idle timeout, closing container stdin');
+  const scheduleClose = () => {
+    if (closeTimer) return; // already scheduled
+    closeTimer = setTimeout(() => {
+      logger.debug({ taskId: task.id }, 'Closing task container after result');
       deps.queue.closeStdin(task.chat_jid);
-    }, IDLE_TIMEOUT);
+    }, TASK_CLOSE_DELAY_MS);
   };
 
   try {
@@ -118,10 +120,9 @@ async function runTask(
           result = streamedOutput.result;
           // Forward result to user (sendMessage handles formatting)
           await deps.sendMessage(task.chat_jid, streamedOutput.result);
-          // Only reset idle timer on actual results, not session-update markers
-          resetIdleTimer();
+          scheduleClose();
         }
-        if (!streamedOutput.result && streamedOutput.status === 'success') {
+        if (streamedOutput.status === 'success') {
           deps.queue.notifyIdle(task.chat_jid);
         }
         if (streamedOutput.status === 'error') {
@@ -130,7 +131,7 @@ async function runTask(
       },
     );
 
-    if (idleTimer) clearTimeout(idleTimer);
+    if (closeTimer) clearTimeout(closeTimer);
 
     if (output.status === 'error') {
       error = output.error || 'Unknown error';
@@ -144,7 +145,7 @@ async function runTask(
       'Task completed',
     );
   } catch (err) {
-    if (idleTimer) clearTimeout(idleTimer);
+    if (closeTimer) clearTimeout(closeTimer);
     error = err instanceof Error ? err.message : String(err);
     logger.error({ taskId: task.id, error }, 'Task failed');
   }