The second review round of p2-4 measured three behaviour defects behind the
as_of feature it had just accepted, and all three came from one mistake: the
code asked "is this memory current?" in three places and answered differently.
- A memory that has closed kept no vector at all, so the dense leg could only
exclude an old fact, never recall it. Vectors now follow existence, not
currency; `_allowed` decides who may see one.
- "Open right now" meant `valid_to IS NULL` in the view and in the words leg
but `valid_to IS NULL OR valid_to > now` in the vector leg, so a supersede
booked for next year hid a fact that is still true today. All three now read
the same rule; schema v12 records the change and the upgrade drops the old
view, since CREATE VIEW IF NOT EXISTS would have kept the old body.
- The dense as_of test was名不副实: dense is off by default, so it passed while
the vector side had no coverage. It now turns dense on with a stand-in model
and pins both `VectorIndex.search(as_of=…)` and the plumbing in retrieval.
Five mutations, each caught by exactly one test: the dense as_of branch, the
retrieval hand-off, the three vector reads, the words-leg currency, the view.
Record side: the round-2 line quoted a D-list I had misread out of the
reviewer's PASS tables (cf2de31 fixed those, and they were its precision notes,
not its findings), the stale line-number parenthetical, an acceptance grep that
scanned CHECKLIST's own quotations, and a Gaps.md tally that disagreed with its
own table (8 closed, 3 closed with reservations, 1 partial).
Gates: 411 passed; ruff, filesize, audit 33/2/6 clean; pyright 0 on the six
touched files; mypy cold cache Success on the same six; scripts/key_test.sh
exit 0 (6 PASS, 1 NOT MEASURED).