docs(weather): normalized-substrate reference — palette256 × helix360

.claude/board/EPIPHANIES.md

@@ -1,3 +1,43 @@
+## 2026-08-11 — E-HELIX360-IS-THE-NORMALIZED-SUBSTRATE-NOT-A-BIT-BUDGET-1
+
+**Status:** FINDING `[G]` for every code fact (file:line in the doc); the weather
+mapping is `[H]`; the floor policy is `[S]` pending probes.
+
+**The finding, in one line:** helix360 is a Fisher-2z-hydratable golden-spiral
+projection — two 24-bit equal-area hemispheres glued at the equator (Poincaré
+rim densification via `arctanh`), stored as the existing 6-byte content-blind
+`ValueTenant::HelixResidue` lane (`U8×6 @ row_offset 112`) whose 2×24 reading IS
+"wind coming from AND going to" — and palette256 is the same mechanism one rank
+down (fisher **z** → u8 → 256×256 LUT = the cosine replacement). The z-form is
+kept **normalized, not materialized**: variance stabilization puts unlike
+variables on one scale, which is what makes cross-variable correlation a
+legitimate LUT operation ("correlate what normally can't be correlated") and
+what makes 8 bits sufficient per scalar. `hyperbolic_depth` being exposed but
+never called in the encode path is the DESIGN, not an unwired seam.
+
+**The one real open decision found by reading `quantize.rs`/`distance.rs`:**
+`RollingFloor` is per-instance and `quantize` is linear over `[lo,hi]`, so
+cross-variable code comparability is a calibration POLICY (shared canonical
+z-floor vs per-variable floors vs hybrid) the weather ingest must set
+explicitly, stamped via `floor_version` and proposed to align with Lance
+dataset versions. Probes P1–P6 queued.
+
+**The correction arc (operator-caught, five instances, one species):** an
+invented 48-bit budget where `Signed360` already existed; a 12-byte `Pair48`
+proposal for a lane already 2× by construction; "unwired 2z" where
+not-materializing is the point; "scalar similarity" where the value is the
+normalization; plus the earlier bearing-snapping/wind-speed measurement
+inversions. Meta-rule: *consult-don't-guess applies to one's own prior
+in-session statements* — they carry no evidentiary weight until checked
+against the tree.
+
+**Doc:** `.claude/knowledge/weather-normalized-substrate.md` (full detail:
+projection, wire shapes incl. the #498 sign-partition regression, floor
+mechanics + loss accounting, measured-evidence ledger with conditions, ingest
+spec with the corrected ARCO-ERA5 object name, verification battery, probe
+queue, correction ledger). Companion plan §0 gains ⊘ C3 (wrong Zarr object
+name) in the same commit.
+
 ## 2026-08-10 — E-CLAUDE-MD-KEY-DEPENDENCIES-WENT-STALE-AND-PROPAGATED-A-WRONG-PIN-INTO-A-PLAN-1
 
 **Status:** FINDING `[G]` (verified against `Cargo.lock` + every crate manifest).