The precondition only asserted the 14:40 bucket EXISTS while its comment claimed
the bucket is short two constituents. It now asserts bar_start moved 14:35 ->
14:37, so the test cannot pass on a fixture where the intended gap failed to
land.

Two surfaces, one wording, after review corrected the causal chain.

THE CHAIN THAT WAS WRONG AS WRITTEN. The first report said "the cached 1min bars
are grid-contiguous within each session, THEREFORE the fix moves no legacy value".
That reads as a claim about residual buckets in general, and in that reading it
contradicts a known fact: the panels leg had 729,029 unclassified cells, so
residual buckets plainly existed. The probe was measuring something narrower.

A residual bucket has exactly TWO causes, reaching different callers:
  1. TRUNCATION -- the materializer pre-truncates at 14:50, so [14:46,14:50] keeps
     four constituents and ends at 14:49. One per trading day; the entire source
     of the 729,029.
  2. A DATA GAP inside a session -- the only cause that can occur without
     truncation.
The legacy / frozen geometry feeds WHOLE-DAY bars, so cause 1 cannot arise there
and its only exposure is cause 2. The probe measures cause 2 (it applies no cutoff
to its input) and finds it empty: 591 symbols, 649,681 (symbol, day) pairs, zero
residual buckets. Both causes excluded -> no-op on the legacy path. The noop test
proves the conditional structurally; the probe supplies its premise on real data;
the A/B corroborates by converging onto the frozen value.

So the probe is not decoration and it is not the whole argument either: it is the
premise of the step that excludes cause 2. Stated without the geometry qualifier
it is simply false, which is how it read.

CATALOGUE (new section, APPENDED at end of file so a concurrent C5-audit append
conflicts mechanically rather than semantically; no existing line is touched).
The section exists mainly to prevent a specific mistake: whoever writes the C5
audit will meet the 729,029 in the run records, and if the catalogue is silent
they may well register it as a difference class to be named and bounded. It must
say the opposite -- F1 is a real engine defect, removed by a correctness fix, and
NEVER a named class. It carries the corrected chain, the per-cell A/B, the
post-fix reconcile counters (unclassified=0 with float_tail / threshold_flip /
flip_contamination all 0 -- nothing was absorbed by a tolerance class), the
no-FactorCorrection ruling with the contrast to PR #103, and the restated verdict.

It also names what WAS contaminated, so the section cannot be read as "nothing
ever went wrong": the live factor_eval_amp_marginal_* artifacts from the C5 full
run are dirty and this branch's rerun overwrites them; the frozen exec baseline
and the eleven-factor v0.9 table are not affected.

DOCSTRING: the same two-cause split, plus the explicit warning not to restate the
measurement as "there are no residual buckets" -- it says nothing about the
truncated geometry, where there is one per trading day.

NOTE this commit edits the factor module, so its code_hash changes and the store
entries filled by the previous run are invalidated even though no value moves.
The real rerun is therefore repeated at this tree, so the reported counters and
the warm store both correspond to the code being handed over rather than to a
superseded one.

…through

Review follow-up, TEXT ONLY -- no behaviour, no judgement threshold, no engine
code. Four fixes, batched into one commit because two of them touch the factor
module's docstring and therefore invalidate its code_hash (measured last round:
cold refill 550.9s vs warm 71.8s), so the real rerun is paid once.

MED-1 -- THE CENSUS SCOPE WAS OVERSTATED, and it was the load-bearing premise.
`f1_residual_probe.py --limit 600` sampled 600 of the ~5,782 CACHED symbol
directories, whose intersection with the 995-name evaluation universe is only
~102. Writing that up as "591 symbols in the evaluation window" invites reading
it as "591 of the 995". Since this premise is what excludes cause 2 (data-gap
residuals) and therefore what makes "no published value moves" true, its scope
has to be exact. Replaced by a FULL census that takes its grid from the frozen
panel itself (`tmp/context/f1_residual_census_full.py`): no sampling, no limit.

  995/995 symbols | 1,159,263 (symbol, day) pairs | 0 residual buckets

1,159,263 is exactly `rows_frozen`, i.e. the census grid coincides cell-for-cell
with the panel the reconcile checks. Measured independently by implementer and
reviewer with different scripts; the numbers agree.

Also recorded: the panels leg already SUBSUMES this census (995 symbols x 1,191
non-warmup days all held to 1e-12). The census earns its place by covering the
other 19 days -- the warmup region, the one place the panels leg does not apply
that tolerance.

LOW-1 -- "no `spec.*` differences" was literally false. Measured: frozen carries
18 `spec.*` leaves, new carries 24. The 18 present on BOTH are value-identical
(including `spec.version` and `spec.description`); 0 removed; the 6 extra are
pure additions (`adjustment` / `lookback_depth` / `overnight_boundary` /
`requires[0..2]`), each `_is_registered_addition == True`, from the D1/D5b
contract rather than from this PR. Restated as "no `spec.*` VALUE changes" in
both places it appears -- this sentence is the argument for not needing a
jump-style correction route, and an argument propped up by a false sentence is
not an argument.

LOW-2 -- the docstring's reason did not match what the rule actually admits. The
criterion asks whether the GRID-BOUNDARY MINUTE IS PRESENT, not how many
constituents a bucket has, and `ceil(09:30, 5min)` is 09:30 -- so the opening
auction minute forms a bucket of ONE and is kept. One 1-minute bar is pooled as
a "5min bar" every trading day. Measured on 600000.SH over 2023-06: 20 of 20
days have exactly one kept sub-5-constituent bucket, always 09:30. Independent
cross-check from the other script: over the first 200 symbols the census counts
233,225 (symbol, day) pairs, the same number the reviewer counted as sub-5
"complete" buckets over the same 200 -- i.e. exactly one per symbol-day.

This sits in tension with the bar-length argument, and it STAYS: both geometries
keep it and so does the frozen baseline, so dropping it would MOVE PUBLISHED
VALUES. That is a separate correctness question owing its own PR and its own
evidence, not something to slip into this one. Said plainly in the docstring and
the catalogue so a later reader does not "fix" it in passing.

LOW-3 -- guard range written into the guard, per house rule. The equality test is
only meaningful where the `freq` grid aligns with the A-share session. Measured:
`{1,5,15,30}min` drop nothing; `60min` drops one bucket per day, because
`ceil(11:30, 60min)` is 12:00, so 11:01-11:30 ends off-grid and the whole morning
close would be discarded daily (600000.SH 2023-06: coarse 100 -> kept 80, every
dropped `bar_end` is 11:30). Latent, not live: `freq` defaults to the module
constant "5min" and both call sites use the default. A 60min caller would get
silent daily data loss rather than an error.

NIT-2 -- test name now matches its fixture. It removes 14:36/14:37, the LEADING
minutes of the 14:36..14:40 bucket, not interior ones; renamed to
`test_bucket_with_a_leading_gap_is_kept_because_its_window_still_closed`. The
first docstring line said "middle minutes" and was wrong in the same way, so it
is fixed too. The leading gap is in fact the stronger fixture: it moves
`bar_start` while leaving `bar_end` on the grid, which is exactly what separates
this rule from a span-based one -- and is why mutation B goes red on it.

DEFECT MAGNITUDE, restated upward. The example first published (000008.SZ, 61
dates, max|diff| 1.42e-04) was too small and too short a window. Re-measured on
600000.SH over the FULL evaluation window (1,213 dates, cache-only): pre-fix
567/1,213 dates differ, max|diff| 4.14e-04, max REL 1.456776e-01; post-fix
0/1,213 differ, max rel exactly 0. The reviewer, loading the pre- and post-fix
modules into one process via `git show main:` and feeding byte-identical inputs,
independently gets max rel 1.457e-01 and whole-day geometry 5/5 BITWISE-EQUAL --
so "no published value moves" is now DIRECTLY DEMONSTRATED, not merely inferred.

Node-ID differential main..HEAD: 2537 -> 2546, 0 removed, 9 added (the rename
stays inside the new file).