Bootstrap: drop identity marker, clarify waiting and command lines

- Remove the "[hcom:name] in your first response" instruction (bootstrap
  and codex fork prompt). Marker-based binding was removed in d66d9958;
  pane titles and `hcom start` output already show who's who.
- Waiting rules: note that `hcom listen` returns early on a message, and
  that it only replaces `sleep` for non-hcom waits.
- Spawn: one example; --hcom-prompt already makes the child report back,
  so the spawner can end its turn. Without it, wait for the ready message.
- events sub: add `--idle <name>` example and --once.
- transcript: add --detailed. list: drop --names/--format (scripting
  flags), which also removes the last {{ }} escape from the template.
- Relay notice: transcript, term, kill, r, f accept name:BOXE.
- Tests check `--name <me>` instead of the marker to detect bootstrap.