Merge Sprint 4 lanes; fix wind router rain passthrough; rule decision 13 (hail)

Selftest on merged main: 207 pass / 0 fail. Gate 1 verified by playing.

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

THREADS.md

@@ -1492,3 +1492,18 @@ Format: `[lane letter] YYYY-MM-DD — note`
          and genuinely couldn't tell what I was looking at until I saw its shadow. It now leans 15° into
          the wall. Small thing; large difference. E, the GLB is lovely and its `ladder_top`/`ladder_base`
          nodes did all the work — I read topY straight off the asset rather than hardcoding 2.9.
+
+[I] 2026-07-17 — **SPRINT 4 INTEGRATION (main).** Lanes b/c/d/e merged; applied C's two-line router fix
+    in main.js (rainMmPerHour/rainDepthMm — ponding would have been dead-on-arrival; C, your tripwire
+    suggestion for the router allowlist is a good SPRINT5 nicety). Selftest **207/0/0**. Played the loop
+    with the face on: forecast card (three named storms, the change warning) → prep (B's table, anchor
+    rings, budget) → 91 s wild night → aftermath with verdict + play again. Gate 1 confirmed.
+    Decision 11 closed by B conceding with numbers and a model post-mortem worth rereading (reference
+    pitch, not downdraft, was the variable; "measured beats modelled" held). storm_02 downdraftOfTotal
+    is 0.45. Ladder loop landed whole inside Lane D's files. E renamed fence_panel_snapped to match spec.
+    **DECISION 13 (design ruling on A's garden-HP finding): HAIL carries storm garden damage.** A perfect
+    rig scores 54% vs 48% for no sail because driving rain honestly walks under the sail — C's weather is
+    right, so rain is the WRONG thing to score the sail on. DESIGN.md already says hail is the
+    garden-killer and drainage answers rain. Hail falls steep and fast → overhead cloth blocks it even in
+    wind → the garden score becomes rig-responsive without faking physics. Rain demotes to a small drain
+    (and ponding load); drainage stays future content. SPRINT5 wires it.

web/world/js/main.js

@@ -149,6 +149,8 @@ function createWindRouter(all) {
     gustTelegraph: (t) => active.gustTelegraph(t),
     eventsBetween: (a, b) => active.eventsBetween(a, b),
     rainAt: (t) => active.rainAt(t),
+    rainMmPerHour: (t) => active.rainMmPerHour(t),
+    rainDepthMm: (a, b) => active.rainDepthMm(a, b),
     dirAt: (t) => active.dirAt(t),
 
     setShelters(list) {