- remove_peer purges only the removed peer's pending acks, not every
peer's (review S9, F13).
- bcast_sent records for an address are dropped when its contact starts
or ends, and a broadcast whose send fails has its record undone, so a
broadcast Ack is accepted only for this contact's dispatched frames
(review S10).
- A repeat Contact for a known peer starts a new contact: it resets the
F6 pin and the per-contact bounce and receipt records (spec §10 F6).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>