The single high-water mark assumed broadcast filenames within one
second were written in sort order; a later broadcast with a lexically
smaller uniq part sorted below an already-advanced watermark and was
silently never delivered to repos that had read the first (review §2).
_broadcast/seen/<repo> now records one delivered filename per line and
delivery is membership-based, removing the ordering assumption. Four
regression checks added first (the ordering check failed against the
watermark), selftest 48/48.
Upgrade note: a legacy single-line watermark file is read as a one-entry
seen set, so pre-existing broadcasts older than the watermark may be
re-delivered once.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HBbjgS5A55RVavoyjJC4FX
coord-send.sh, coord-inbox.sh, coord-done.sh and the 40-check
coord-selftest.sh, unchanged, as the extraction baseline. Selftest
passes 40/40 in this location (script paths are dir-relative).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HBbjgS5A55RVavoyjJC4FX
