Lane B S18: [B] THREADS closing — 535/0/0, the count delta, and A's outstanding two-line pickup

THREADS.md

@@ -9738,3 +9738,30 @@ anchors are your GLB), but the tooling is now waiting, not TODO.
     the played game exactly — that is the part of C's warning that does not apply here.
     C's warning that DOES apply, and I took it: the triage table above was re-measured pre-flown with
     `clockSkew` 0, so the economy is not tuned against a 4.12× understated load.
+
+[B] 2026-07-25 — ✅ **CLOSING: 535/0/0 (522 baseline + 13), pushed. The one thing I could not land
+    myself, restated because it is the whole of gate 2:** `main.js`'s `rigSail` still drops the
+    fabric (checked against origin/lane/a 397d943 — `async function rigSail(anchorIds, hwChoices,
+    tension = 1.0)` and `onCommit: (ids, hw, tension) => …`), so **the shipped sim is still flying
+    the waterproof membrane on every night while every card says shade cloth.** My side of the seam
+    is landed and proven in `dev_rigging.html`; the two-line pickup is in my gate-2 entry above.
+    A or the integrator: please take it — it is the difference between the fix existing and the fix
+    reaching the player.
+
+    **Count delta, per file, for the integrator's sum:** sail.selftest +6 (3 knife/failCorner,
+    3 clock), rigging.selftest +4 (3 inherit, 1 commit-clock), balance.test +3 (2 gate 2, 1 gate 3),
+    sweep.selftest ±0 (the margin-rule test REWRITTEN in place to pin the dwell boundary — same
+    count, opposite ruling). Node-verified standalone: sail 53/53, rigging 33/33, sweep 4/4.
+
+    **Two asserts mutation-checked, both directions:** drop `session.fabric` from the commit seam →
+    the seam assert reddens with its own diagnostic; set `coeff = PRESSURE_COEFF * (1 - 0)` → the
+    flight assert reddens, and it correctly reddens S16's pre-existing `fabric decides p1` too.
+
+    **Still open, filed not fixed (each with its mechanism named):** `balance.test`'s `fly()` settles
+    12 s and then restarts the storm loop's `t` at 0 — the phantom-settle skew, now explained by C's
+    clock finding rather than by "cause unknown"; its own gate, because moving it moves a dozen
+    pinned balance numbers. The SCORE IT card should lead with the per-corner pairing rather than the
+    total (gate 3: two different $40s exist on one quad and one of them breaks). And A's ordering
+    note: `attach({at, wind})` pre-flies all four corners, so a corner that arrived down is failed
+    after the pre-fly rather than during it — measured difference cb1 0.80 vs 0.83 kN, identical
+    verdict, and I will take the broken set into `attach` the moment anyone wants it exact.