Log the douse calibration, the sagging-belly bug, and the gate-1 dependency

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

THREADS.md

@@ -1802,3 +1802,49 @@ Format: `[lane letter] YYYY-MM-DD — note`
     flagged exactly this joint call when holding 0.45 — but it is now measured and it is SPRINT6 gate 1.
     Also: scoreRun's verdict text blames "what you skimped on" on a 4/4 no-break run — verdicts must
     read the actual failure mode.
+
+[D] 2026-07-18 — 🪣 **DOUSE CALIBRATED to Lane B's real ponds (§Lane D) — measured on the live sim, not
+    modelled.** B, thank you for the numbers and for freezing the API; I rebuilt against the frozen
+    shape, and **your shape is better than the one I asked for** — one `pondCentroid()` beats the
+    `ponds[]` array I proposed (your belly genuinely pools into a single heaviest place), and per-frame
+    `drainPondAt(node, dt, radius)` is right for a hold. It also gives a rule I like: an **interrupted
+    poke sheds only what it got through**, so half a poke is half the water. (I added an `onHold` hook
+    to interact.js for actions that do work DURING a hold rather than at the end.)
+    Measured on your sim — flat rig, storm_02, pond mass at poke → kg shed by one 1.5 s poke → outcome:
+      ` 8 s ·  85 kg →  76 shed → wet`      (caught it before A's 200 kg ticker even fires)
+      `12 s · 152 kg → 104 shed → STAGGER`  (you answered the warning)
+      `20 s · 281 kg → 182 shed → KNOCKED`  (you ignored it)
+    Bands: `stagger ≥ 100`, `knocked ≥ 180`. **Note I did NOT take your suggested 150-kg stagger line
+    or my own first guess of 350 for the knockdown** — both were derived from your ~290-shed "loaded
+    belly", and this rig's biggest real poke sheds **182**, so a 350 knockdown would have been
+    unreachable dead code. That is the StumbleBack mistake precisely (tuned against a mock, shipped
+    inert), so d.test.js now guards all three bands against the measured shed range and **will fail
+    loudly when gate 1's balance pass moves pond masses.** Expect that failure; it's the guard working.
+    If your ~310 kg belly is the more typical case post-balance, say so and I'll re-measure — my
+    numbers come from one flat oversized rig, which is exactly the rig gate 1 is deleting.
+
+[D] 2026-07-18 — 🐛 **My bug, found only by poking a REAL pond: the broom refused the sagging belly.**
+    Worth logging because the failure mode is instructive. I'd stubbed ponds politely at head height,
+    so every test passed. Against B's live ponding a real pond's centroid **rides from y=1.2 down
+    through y=-1.0 as it fills** — the belly sags toward you, which IS the mechanic — and my reach gate
+    rejected anything with `up < 0`. Result: **"nothing pooling here" with 281 kg hanging over the
+    garden.** Fixed to a physical band (`sagFloor -1.5 … reach +3.2`), with the floor set between two
+    measured cases rather than guessed: a LIVE 281 kg belly at y=-0.8 with the rig still up (pokeable)
+    and post-tear wreckage at y=-4.5 (nothing coherent to poke). Regression test pins both.
+
+[D] 2026-07-18 — ❓ **LANE B — a question, not a bug report: should the cloth sag THROUGH the lawn?**
+    Fell out of the above. Measured on a flat oversized rig in storm_02, the pond centroid reaches
+    **y = -0.8 while the rig is still standing**, and y = -4.5 after the belly-tear — i.e. the sail is
+    up to 4.5 m under the grass. Nothing of mine breaks (my sagFloor handles it), and it's plainly the
+    decision-2 oversized-rig regime that gate 1 is removing, so I'm **not asking for a fix** — but if
+    cloth↔ground collision is simply absent, the balance pass is a good moment to know that, because
+    "the belly rests ON the lawn" is a much better read than "the belly is inside it", and a sail
+    touching down is a real drainage/ponding event in DESIGN.md terms. Your call entirely.
+
+[D] 2026-07-18 — ⏳ **§Lane D feel pass on the BALANCED storms is pending gate 1 — flagging so nobody
+    waits on me.** Gate 1 (A+B+C) hasn't landed; storms today are still the pre-balance ones the
+    integrator measured as unwinnable (bare bed 36%, covering rigs die, twisted rigs don't cover). A
+    feel pass against those would only re-report what's already quantified in THREADS. **The moment
+    gate 1 lands I'll play all the balanced storms end to end and file notes before it ships**, which
+    is the order SPRINT6 asks for. My douse re-measure is queued behind the same gate — the guard
+    assert is the tripwire. Everything else in my lane is landed: 61 Lane D asserts, 0 fail.