Summary of one session .jsonl file.
See ClaudeWrapper.History for how these are produced.
Summary
Types
@type t() :: %ClaudeWrapper.History.SessionSummary{ first_timestamp: String.t() | nil, first_user_preview: String.t() | nil, last_timestamp: String.t() | nil, message_count: non_neg_integer(), project_slug: String.t(), session_id: String.t(), size_bytes: non_neg_integer(), title: String.t() | nil, total_cost_usd: float() | nil, total_tokens: non_neg_integer() | nil }