Lists subagent IDs for a given session by scanning the subagents directory.
Subagent transcripts are stored at ~/.claude/projects/<dir>/<sessionId>/subagents/agent-<agentId>.jsonl.
~/.claude/projects/<dir>/<sessionId>/subagents/agent-<agentId>.jsonl
Optional
Array of subagent ID strings, or empty array if none found
Lists subagent IDs for a given session by scanning the subagents directory.
Subagent transcripts are stored at
~/.claude/projects/<dir>/<sessionId>/subagents/agent-<agentId>.jsonl.