- Spawns Claude Code CLI with stream-json output in session directories
- Reads stdout/stderr concurrently via asyncio.gather (no pipe deadlock)
- Handles process lifecycle with clean termination (no zombies)
- Queues messages during processing using asyncio.Queue
- Auto-restarts on crash with --continue flag (max 3 retries)
- Parses stream-json events (assistant, result, system) to callbacks
- Supports persona configuration (system_prompt, model, max_turns)
- Uses terminate() + wait_for() + kill() fallback pattern
Based on research: .planning/phases/01-session-process-foundation/01-RESEARCH.md
