fix(async-tasks): wake the parent conversation by id, not by source

DurableSink resumed the parent through ChatHub::resume(&source), which
resolves whatever session the source currently points at. Since one
source can now carry several conversations (secondary tabs, a reset
since the task started), that pointer is no longer the conversation the
result was delivered into: the recovery ran on the wrong one, found
nothing pending, and returned silently — the delivered task_completed
sat unread until the user's next message drove a normal turn.

The sink already knows the parent session id, so resume it directly
through resume_for_session, keeping the same in-flight guard. The
source lookup and the now-unused pool field go with it.

Adds a crate-level regression test: a completed turn, a StoreSink
delivery, then a recovery — the result must drive a new round.

crates/agent-loop/tests/recovery.rs

@@ -379,6 +379,34 @@ async fn an_interrupted_parallel_batch_is_reaped_and_the_parent_resumes() {
     assert_eq!(report.frames_resumed, 1, "the root continues with the failures in view");
 }
 
+// ── async result wake-up (reproduction) ──────────────────────────────────────
+
+#[tokio::test]
+async fn an_idle_conversation_woken_by_an_async_result_continues() {
+    use agent_loop::delegate::{AsyncResultSink, CompletedTask, StoreSink};
+    use agent_loop::ids::TaskId;
+
+    let h = H::new(vec![Step::message("processing the task result")], vec![]).await;
+
+    // The parent's turn is complete: user message, final assistant reply.
+    h.store.append(h.root, NewMessage::user("start a task")).await.unwrap();
+    h.store.append(h.root, NewMessage::assistant("started, I'll let you know", None)).await.unwrap();
+
+    // The task finishes: the sink writes the synthetic delivery, then the host
+    // wakes the conversation with a recovery.
+    let sink = StoreSink::new(h.store.clone());
+    sink.deliver(h.conv.clone(), CompletedTask {
+        id:     TaskId(7),
+        title:  "research".into(),
+        result: "the answer is 42".into(),
+    })
+    .await
+    .unwrap();
+
+    let report = h.recover().await;
+    assert_eq!(report.frames_resumed, 1, "the delivered result must drive a new round");
+}
+
 // ── resolve_pending ──────────────────────────────────────────────────────────
 
 #[tokio::test]

crates/skald-core/src/loop_adapters/async_task.rs

@@ -99,17 +99,20 @@ impl AsyncExecutor for CronExecutor {
 ///
 /// `ChatHub::resume` skips a session with a turn already in flight, which is the
 /// right rule here too: a live loop reads the store each round and picks the
-/// result up on its own.
+/// result up on its own. The wake-up addresses the parent **by session id**,
+/// never by source: one source may now carry several conversations (secondary
+/// tabs) or have moved to a fresh one since the task started, and resuming the
+/// source's active session would run the recovery on the wrong conversation —
+/// a silent no-op there, while this result sat unread until the next message.
 pub struct DurableSink {
     inner: StoreSink,
-    pool:  Arc<SqlitePool>,
     hub:   Arc<ChatHub>,
 }
 
 impl DurableSink {
     pub fn new(pool: Arc<SqlitePool>, hub: Arc<ChatHub>) -> Self {
-        let store: Arc<dyn HistoryStore> = Arc::new(SqliteHistory::new(pool.clone()));
+        let store: Arc<dyn HistoryStore> = Arc::new(SqliteHistory::new(pool));
-        Self { inner: StoreSink::new(store), pool, hub }
+        Self { inner: StoreSink::new(store), hub }
     }
 }
 
@@ -119,10 +122,6 @@ impl AsyncResultSink for DurableSink {
         self.inner.deliver(parent.clone(), task).await?;
 
         let session_id = SqliteHistory::session_id(&parent)?;
-        let source = crate::db::chat_sessions::find_by_id(&self.pool, session_id)
+        self.hub.resume_for_session(session_id).await
-            .await?
-            .map(|s| s.source)
-            .ok_or_else(|| anyhow::anyhow!("deliver: session {session_id} not found"))?;
-        self.hub.resume(&source).await
     }
 }