CB-WP-0025 T06/T07: a difficulty baseline that reports its own confound

T06. games/ground/examples/difficulty.rs, make difficulty, wired into make
self-tests, and a report file in ground-game under GROUND-WP-0005 with a
hub message pointing at it.

THE REPORT OPENS WITH THE RETRACTION, because what this task was written
to send was withdrawn by T02 and GROUND-WP-0005 is blocked on exactly that
number. They are told, in the first section, that we nearly sent them "the
game is too easy at 5-6 seats" and why it was wrong.

  seats  winnable  greedy  random  first-legal  spread
   2p      60%     60.0%    5.0%      76.7%      71.7
   3p      93%     88.3%    6.7%      25.0%      81.7
   4p     100%     93.3%    6.7%      30.0%      86.7
   5p     100%    100.0%    3.3%       0.0%     100.0
   6p     100%    100.0%    3.3%       0.0%     100.0

SPREAD justifies the whole redesign: 71.7 to 100.0 points between three
trivial policies. The table now shows why no single rate is a difficulty
rather than asserting it.

And the 5-6 rows point the OPPOSITE way from the withdrawn claim --
first-legal 0% against greedy 100% is the widest spread in the table,
which suggests play matters MORE there, not less. Neither reading is
established and the report says so.

The confound is stated in the tool's own output, not only in prose:
`winnable` is conditioned on greedy's play up to the final round, because
searching from round 1 is unaffordable. Presenting it as a property of the
deal would repeat this pass's error in a subtler form -- which is exactly
how a corrected project reintroduces a defect. NO THRESHOLD CHANGES ARE
PROPOSED.

The instrument can fail (spec §5): a witness must replay to a win, an
unwinnable position must report searched-out rather than a budget cut, a
one-node budget must not claim exhaustion, and the policy panel must
actually disagree. difficulty-baseline.rs marked superseded, kept as the
survey's dated snapshot. Registered as F16, inconsistent / withdrawn.

T07. evidence/CB-EV-0024. Five of nine defects came only from the review;
four from execution, and all four of those were in work written after it.
The wrong-denominator family now has five instances and still no control
-- facts-check catches copies that disagree, nothing catches a number
computed correctly against the wrong base. Tier L was an over-declaration
(no port, structurally M) and paid for itself anyway, because the review
is L-only. Chaos window 2 will close with zero overrides, making its
retirement condition untestable.

Named as open rather than implied done: the witness is NOT wired to the
ending page. The search works; the browser cannot ask it yet.

make all: exit 0. loop-lint clean.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

specs/FindingRegister.md

@@ -43,6 +43,7 @@ kinds, states and metrics: [`GameDesign.md`](GameDesign.md). Reported by
 | F13 | inconsistent | withdrawn | scenarios/ground/gr-e01-threshold-reachable-2p.yaml | counterexample | 2026-08-01 | clay-borg |
 | F14 | unplayed | note | — | — | 2026-08-01 | clay-borg |
 | F15 | underdetermined | note | — | — | 2026-08-05 | clay-borg |
+| F16 | inconsistent | withdrawn | games/ground/examples/difficulty.rs | counterexample | 2026-08-05 | clay-borg |
 
 <!-- design-register:end -->
 
@@ -62,6 +63,16 @@ kinds, states and metrics: [`GameDesign.md`](GameDesign.md). Reported by
   `-reachable-`. **Its reproduction is green**, which under GameDesign §1.3
   is the alarm that forced the resolution. Withdrawn rather than deleted,
   and the withdrawal is reported (ADR-0012 D5).
+- **F16 — "the game is too easy at 5–6 seats", withdrawn the day it was
+  raised.** Claimed from `GreedyPolicy` winning 200/200 at those seat
+  counts. A `FirstLegal` policy scores **0%** on the identical deals, and
+  at two seats it *beats* greedy — two unsophisticated agents span the
+  whole range, so the measurement was about the policy. Caught by the
+  CB-WP-0025 adversarial review (C4) **before transmission**; it would
+  have been the fifth wrong premise sent to ground-game and the worst,
+  since GROUND-WP-0005 is blocked on exactly this number. The withdrawal
+  was reported (ADR-0012 D5). Its reproduction is `difficulty.rs`, whose
+  policy panel is plural *because of this finding*.
 - **F15 — the rules define one game, not a series.** `OutcomeView` gives
   `personal` (per seat), `group_success` (per table) and `winners`. Summing
   the first and counting the third answer different questions, and GROUND