Lightweight session metadata for the session picker and history display.
Contains just enough information to render a session list entry without
loading the full conversation history. Built from session state via
from_state/1 or loaded from the session store.
Summary
Types
@type t() :: %MingaAgent.SessionMetadata{ cost: float(), created_at: DateTime.t(), first_prompt: String.t() | nil, id: String.t(), message_count: non_neg_integer(), model_name: String.t(), status: MingaAgent.Session.status() }
Session metadata.