# Quick Task 260414-8co: Wire deferred delivery into SubagentStart hook messages

## What Changed

Changed `hook_subagent_start.rs` to use `send::deliver_body_deferred()` instead of `send::deliver_body()` for the WORKING_PERCH_NOTICE message sent to the parent agent.

## Why

SubagentStart hook notices are low-priority automated messages announcing working perch creation. Using TCP-first delivery (`deliver_body`) wakes the parent agent unnecessarily — these notices should arrive on the natural hook cadence (PreToolUse/UserPromptSubmit) via spool-only delivery.

## Key Files

- `src/owl/hook_subagent_start.rs` — switched from `deliver_body` to `deliver_body_deferred`

## Side Effects

- `deliver_body_deferred` is no longer dead code (was producing a compiler warning)
- Parent agents will no longer receive TCP wake signals for working perch notices
- SubagentStop hook was not changed — it doesn't send any messages (only cleans up perch directory)

## Commit

- `5e4e80d`: fix(quick-260414-8co): use deferred delivery for SubagentStart hook notices