//! Lightweight header-only session parse for fast directory scanning.
//!
//! When searching for a session that matches a workspace, we only need the
//! `metadata.directory` field. This struct deserializes that plus a few
//! other small fields; serde_json still lexes past the heavy
//! `messages`/`tool_uses` arrays but never allocates a `Vec<Message>`,
//! which is the dominant cost for multi-megabyte session files.
use Deserialize;
use SessionMetadata;
pub