Function session_task_store 

pub fn session_task_store(
    streams: &Arc<StreamRegistry>,
    default_ttl_ms: Option<u64>,
) -> Arc<TaskManager> 

Build a per-session task store that publishes notifications/tasks/status onto the session’s SSE stream registry.

Every HTTP adapter creates its TaskManager and StreamRegistry together per session; this is the one place that wires them, so an adapter cannot forget to and silently stop emitting the notification.

default_ttl_ms mirrors TaskManager::with_default_ttl.