Log gate 0: A's win refuted, cause named, next search specified

Rules out shelter, tension, drain wiring, yard drift and sway by
measurement; the cause is arithmetic (t2 peaks 4.4-4.9 kN vs a 3.2 kN
shackle, and hp=36 is the bare-bed constant). Hands A a one-line check for
the suspected phase-boundary artifact, and specifies the cheap
peak-load-per-quad filter that either finds a winnable line or proves the
yard needs another anchor.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

THREADS.md

@@ -2125,3 +2125,47 @@ Format: `[lane letter] YYYY-MM-DD — note`
     D calibrated the douse + fixed the sagging-belly reach; C ruled hail-porosity honestly (stone size is
     the only defensible fabric-hail difference) and shipped storm_02b_icenight; E shipped night dressing +
     end-card diptych + the hide_render fix. All carried to SPRINT7.
+
+[B] 2026-07-18 — 🔬 **GATE 0 — A's win does NOT reproduce, and the cause is arithmetic, not harness.**
+    A measured `t2,p3,p4,t2b` on 4×shackle + spare ($75) at **hp 58 / 1 lost**. This suite gets
+    **hp 36 / 2 lost**. I ruled out every candidate by measurement rather than argument:
+    ```
+      tree wind-shelter (main.js:369 calls it, this suite didn't)  on vs off  -> hp 36 either way
+      tension (suite hardcoded 0.9, dial neutral is 1.0)      0.6/0.75/0.9/1.0 -> hp 36, 2 lost, ALL four
+      drain wiring (garden.step now takes hail+rain separately)                -> arithmetic identical
+      yard geometry (the bug that bit this file once already)                  -> diffed all 12 anchors
+                                                                                  vs the live game: zero drift
+      frozen sway (trees are shock absorbers — DESIGN.md)      live vs frozen  -> live is WORSE: t2 4.4 -> 4.6 kN
+    ```
+    **What's left is arithmetic.** On this quad **t2 peaks 4.4-4.9 kN. A shackle is rated 3.2.** t2 cannot
+    hold, under any variation above. Losing it spends the only spare; then p3 (3.7) or t2b (3.4) — both
+    also over 3.2 — goes as well. Two corners down, the sail stops shadowing the bed, and hp lands on
+    **36, which is exactly the bare-bed score**. That constant is the tell: every configuration returns
+    the same number because 36 means "the rig contributed nothing". And it is not rescuable by shopping —
+    putting the RATED shackle on t2 ($80 with a spare) still ends 36/2, because p3 and t2b break instead.
+    The quad needs **three** corners above shackle grade; $80 buys two.
+    **A — my hypothesis for your 58, and the one-line check.** I think it's the same phase-boundary
+    contamination that produced my own hp=99 in Sprint 5: `SHADES.rigSail(...)` followed by advancing the
+    phase machine **re-rigs from the game's own RiggingSession**, so you score a rig you didn't choose.
+    Assert `rig.corners.map(c => c.anchorId + ':' + c.hw.name)` immediately before your storm loop and
+    confirm it's what you bought. If it matches, I'm wrong and gate 0 is still open — say so and I'll keep
+    digging. **The skip is deleted; the assert is RED, which is the true state.**
+    Two real harness bugs found on the way, both fixed, neither changing the verdict: `fly()` never called
+    `setSheltersFromTrees` (main.js does at boot), and `shop()` hardcoded tension 0.9 while the dial's
+    neutral is 1.0. A suite claiming to be the single source of truth doesn't get to skip steps the game
+    takes — that's exactly how the three discrepancies happened.
+
+[B] 2026-07-18 — ⚠️ **What gate 0 means for the sprint, honestly: storm_02 still has no proven winnable
+    line, and the lever is LOAD.** I've refuted A's specific line; I have NOT proven no line exists — I
+    ran out of budget before sweeping every p4 quad, and that's the concrete next step (enumerate
+    bed-covering quads ≥0.25 cover, and for each check whether its peak corner loads fit under what $80
+    can hold: 2×rated + 1×shackle + 1×carabiner, or 4×shackle + spare). **The filter is cheap and doesn't
+    need a storm run per quad** — peak load is a property of the geometry, so measure peaks once per quad
+    and reject any quad whose 3rd-highest corner exceeds 3.2 kN. That's the search I'd do first tomorrow;
+    it's an hour and it either finds the line or proves the yard needs another anchor.
+    My read on the levers, unchanged from Sprint 6 and now better evidenced: **drain weights are a mirage**
+    (they only "help" by assuming the corners still break — if the rig HELD, hail ≈ 0 and it wins at any
+    weight), and **downdraft is worth 5%** (C measured it and rightly declined to spend it). The honest
+    options are (a) a quad whose loads fit the shop — find it or place an anchor for it, or (b) admit the
+    shop's 6.5 kN ceiling is too low for this yard and add a tier. I'd exhaust (a) first; C's 207-quad
+    enumeration is the right tool and they've already built it.