Changed
- Session persistence: Subagent sessions are now stored alongside the parent session file instead of
/tmp. If the parent session is~/.pi/agent/sessions/abc123.jsonl, subagent sessions go to~/.pi/agent/sessions/abc123/{runId}/run-{N}/. This enables tracking subagent performance over time, analyzing token usage patterns, and debugging past delegations. Falls back to a unique temp directory when no parent session exists (API/headless mode).