Restore active sessions on startup

app/agent/orchestrator.py

@@ -82,6 +82,34 @@ class AgentOrchestrator:
         logger.info(f"Started session {session_id} for {channel_name}")
         return session_id
 
+    async def restore_active_sessions(self) -> int:
+        """Restore active sessions from the database after app startup."""
+        restored_count = 0
+
+        async for db_session in get_session():
+            repo = Repository(db_session)
+            sessions = await repo.get_active_sessions()
+
+            for session in sessions:
+                recent_messages = await repo.get_recent_messages(session.id, limit=1)
+                message_count = await repo.count_messages(session.id)
+                last_activity_at = (
+                    recent_messages[0].timestamp if recent_messages else session.started_at
+                )
+
+                self.active_sessions[session.id] = {
+                    "channel_name": session.channel_name,
+                    "started_at": session.started_at,
+                    "message_count": message_count,
+                    "theme": session.theme,
+                    "last_hearthkeeper_prompt_at": None,
+                }
+                self.chat_activity.record_activity(session.id, occurred_at=last_activity_at)
+                restored_count += 1
+
+        logger.info(f"Restored {restored_count} active sessions")
+        return restored_count
+
     async def end_session(self, session_id: str) -> None:
         """
         End a stream session and trigger ledger generation.