Two advisory flags on the issue-flow sweep, the mechanical backstop for
#288's collision rule and #292's window rule. Both are prose today, and
both failed silently on the same morning: #284 was minted `ready` into a
file another issue held claimed with a PR in flight, and six `ready`
non-members raced an emptying gate. #262 measured the pattern — the same
class of rule, once in a guard, produced zero misses.
Comments only (D1): no label write, no state change, no new label. The
sweep never guesses intent; it states the board fact and triage resolves.
The collision key is the title's em-dash prefix NORMALIZED, because the
2026-08-04 miss spelled one deliverable two ways — `actions/issueflow-reconcile`
against bare `issueflow-reconcile` — so exact-prefix matching would have
missed the pair it was written for. One leading path segment comes off,
then every extension; a `+`-joined title matches on any segment.
The flag asks for a CHAIN, not a fan (#288 D3): within one key each issue
names the newest open carrier below it, so the declaration it asks for
releases exactly one successor per close.
A standing window is a release issue whose gate still holds an OPEN member.
The board read IS the open set, so membership decides openness with no
extra call, and an all-closed gate is the emptied gate the release's own
blocked -> ready promotion answers — which is why a `ready` release leaves
the flag dormant instead of flagging the whole board.
Dedup is the declaration echo's, extracted into state_marker /
state_echo_needed and scoped per family (D4): the marker is keyed to the
offending state's value and compared against that family's last word on
the thread, so a state that changes always speaks.
Fixtures replay the 2026-08-04 morning board whole and the post-ruling
board beside it: the first draws exactly four collision flags and six
window flags and writes not one label; the second draws none.
Closes#293.
