Codex: failure recalls inside a subagent are recorded under a session no trace will have #157

Inside a Codex subagent, hook payloads carry agent_id and session_id is the subagent's thread id. The adapter skips subagent prompts but not subagent PostToolUse, so a failing command there injects a procedure and records the injection under the child thread's id. Subagent rollouts are learned through their parent, whose trace has a different id, so the injection is never settled: its outcome is never scored and it stays in the store.

Applies to the agent support in #149.

Files:

• crates/trodden/src/harness/codex.rs

Fix idea: ignore PostToolUse (and Stop / PreCompact) when agent_id is set.