probe: h268-probe-wave-v1 — WH-MAG (NEUTRAL), SIG-CHECKSUM (PASS), WALK-SPECTRUM (KILL of §10(g) decorrelation half)

.claude/board/EPIPHANIES.md

@@ -1,3 +1,11 @@
+## 2026-07-16 — E-H268-PROBE-WAVE-1-RESULTS — three H.268 conjectures measured: WH-tile NEUTRAL/not-transferring, signature-checksum PASS (depth-2 blind spot), walk-spectrum KILL of §10(g)'s "decorrelated" half
+
+**Status:** FINDING (three probes run against shipped code, deterministic seeds, Opus-adjudicated; grades E-WH-TWO-SIDES-SIG-CHECKSUM-1 legs 1+2 and §10(g); plan `h268-probe-wave-v1.md`). No canon changed; one claim-leg CLOSED NOT-TRANSFERRING, one KILLED, one PASSes with a bounded caveat.
+**P1 PROBE-WH-MAG → NEUTRAL (negative-leaning); the [H] bare-tile leg CLOSED NOT-TRANSFERRING.** Per-class MSE ratio B/A (WH-rotate-then-cascade ÷ direct i4+i2 — the probe isolates WH pre-rotation as the ONLY variable, a uniform cascade on both paths, not the shipped I4I2 branch), 256 tiles/class, 16-cell tiles: gradient+spike **0.929**, heavy-tailed **1.317**, uniform-noise **1.869**. Misses the <0.9 PASS bar on every class and regresses past 1.1 on two — adjudicated NEUTRAL (strict KILL bar of >1.1 on ALL unmet). Mechanism: WHT₁₆ spreads a tile's outlier energy across all 16 cells (≈1/√16 each), inflating the per-cell quantization floor where the direct cascade quantized 13-14 near-zero cells almost for free. WH helps only where energy is already spread (smooth gradient, 0.929) or where the outlier escapes to a passthrough tier first. The 16-cell probe has NO passthrough escape and NO centroid residual — exactly the two things the shipped row codec (E-PALETTE-RESIDUAL-LADDER-1) pairs WH with — so the row-level win does not transfer to bare per-tile granularity, and the shipped row codec is untouched. Follow-up PROBE-WH-MAG-2 (WH + per-tile passthrough escape + centroid residual) NAMED but DEFERRED — worth running only if a per-tile adaptive-codec consumer materializes (e.g. the geo-elevation continuous-field exit at 4×4 granularity, where 0.929 is a real if sub-threshold thread).
+**P2 PROBE-SIG-CHECKSUM → PASS, with a depth-2 blind-spot bound in the verdict.** All three green at Pillar-11's own thresholds: replay-identity bit-exact (Frobenius 0.0), tree-like A→B→A mid-path excursion invisible (0.0 < 1e-9), non-tree interior displacement caught (11.31 > 0.05; level-1 delta 0.0 — level-2 signed area does the discriminating). Caveat (exact identity, not approximation): at DEPTH=2 the digest's null space is strictly LARGER than tree-like equivalence — a non-backtracking interior displacement by an offset PARALLEL to the neighbor chord `path[i+1]−path[i−1]` produces EXACTLY zero signature change (½(off⊗chord − chord⊗off) vanishes when off ∥ chord; level-1 is endpoint-invariant). The probe's `displace_interior_point` picks a perpendicular offset precisely to dodge this null space. Consequence: do NOT claim the depth-2 digest catches all non-tree edits — it catches all with non-zero signed-area component. Mitigable by depth 3 or a paired independently-projected second digest.
+**P3 PROBE-WALK-SPECTRUM → KILL of §10(g)'s "decorrelated from the palette lattice by construction" half; the "known period-17 structure" half CONFIRMED.** Walk period-17 harmonics |R| = 0.998/0.996/0.994 (closed form R(17m)=1−8m/N, N=4096) — the KNOWN structure exactly as predicted. But walk |R| at palette-lattice periods peaks at 0.875 (τ=64) vs the LCG baseline's lattice max 0.0205 → 42.7×, far past the 3× KILL bar. Verified by hand: the parity of a full-period-17 coprime-walk permutation is an EXACT period-17 ±1 waveform, so R(τ) is governed by C(τ mod 17) at every lag; τ=64 → 64 mod 17 = 13 → C(13)=C(4)=−15 → −15/17 ≈ −0.882 ≈ measured −0.875. `gcd(17,τ)=1` guarantees a full-period permutation, NOT low autocorrelation (C(4)=−15 is near the ±16 maximum). Corrected claim: the walk gives KNOWN/replayable/self-testable structure (auditability + the period-permutation conformance self-test) — NOT low lattice correlation; the "anti-moiré in concept space / friendlier to I-NOISE-FLOOR-JIRAK" consequence is STRUCK (strong periodic autocorrelation is if anything worse for weak-dependence rates than a PRNG's ≈−1/N floor). Genuine decorrelation, if ever needed, requires a DESIGNED low-autocorrelation sequence (Legendre/quadratic-residue Paley over a prime p≫17, or a maximal-length LFSR m-sequence). Unaffected: the walk's bijectivity/quantization role and OGAR D-QUANTGATE stay canon (the coprime walk QUANTIZES by construction — bijective closure + WGSL-portable integer stride — which this probe neither tests nor challenges); the KILL is scoped strictly to the anti-moiré decorrelation consequence as originally worded.
+**Cross-ref:** E-WH-TWO-SIDES-SIG-CHECKSUM-1 (leg 1 CLOSED not-transferring for bare tiles, leg 2 PASS with caveat), E-PALETTE-RESIDUAL-LADDER-1 (shipped row codec, untouched), E-H268-REPLAYABLE-TILE-1 §(g) (KILLED as worded), I-NOISE-FLOOR-JIRAK, ndarray `pr-x12-h268-morton-wgpu-synergies.md` §5 results sub-table + §10 re-grades + §10(g) correction, plan `h268-probe-wave-v1.md` Results. Probes: `crates/bgz-tensor/src/adaptive_codec.rs` mod probe_wh_mag, `crates/jc/src/sig_checksum.rs`, `crates/helix/src/walk_spectrum.rs` — deterministic; graded probes (P1/P3) assert only structural sanity, P2 asserts a deterministic identity by design.
+
 ## 2026-07-16 — E-WH-TWO-SIDES-SIG-CHECKSUM-1 — one Walsh–Hadamard family for both pyramid sides; Hambly–Lyons signature as the replayable-trajectory checksum (probe-gated forward synthesis)
 
 **Status:** CONJECTURE (operator-proposed synthesis; [H] and [S] respectively; two named probes; nothing shipped, no canon changed).

.claude/board/INTEGRATION_PLANS.md

@@ -1,3 +1,18 @@
+## 2026-07-16 — h268-probe-wave v1 — ACTIVE
+
+**Plan:** `.claude/plans/h268-probe-wave-v1.md`
+**Scope:** convert three cheap conjectures from the merged H.268 arc
+(ndarray #242-#245 / lance-graph #695-#701) into measured verdicts,
+CPU-only, no new deps: PROBE-WH-MAG (WHT₁₆ magnitude preconditioner vs
+direct i4+i2, in bgz-tensor — grades E-WH-TWO-SIDES-SIG-CHECKSUM-1 leg 1),
+PROBE-SIG-CHECKSUM (depth-2 signature as replayable trajectory digest, in
+jc behind `hambly-lyons` — leg 2), PROBE-WALK-SPECTRUM (stride-4-mod-17
+autocorrelation vs PRNG baseline at palette-lattice periods, in helix —
+grades §10(g) anti-confabulation). Explicit non-scope: PROBE-GPU-LUT
+(wgpu), OGAR PHASE-1/PERT-RHO/PYR-1, A8. Sonnet drafters + Opus
+adjudication; autonomous merge after clean CI/review (operator-granted
+this goal).
+
 ## 2026-07-10 — temporal-markov-and-style-classes v1 — ACTIVE
 
 **Plan:** `.claude/plans/temporal-markov-and-style-classes-v1.md`

.claude/plans/h268-probe-wave-v1.md

@@ -0,0 +1,184 @@
+# H.268 Probe Wave v1 — WH-MAG · SIG-CHECKSUM · WALK-SPECTRUM
+
+> Date: 2026-07-16. Status: ACTIVE (this session, autoattended).
+> Parent arc: the H.268 documentation arc (ndarray #242-#245, lance-graph
+> #695-#701, all MERGED). This wave converts three of its cheapest
+> conjectures into measured verdicts. Everything runs CPU-only against
+> shipped code; the heavier gates (PROBE-GPU-LUT wgpu harness, OGAR
+> PHASE-1/PERT-RHO/PYR-1, A8) are explicitly OUT of this wave.
+> Execution model per operator directive: Sonnet drafters (grindwork,
+> edit-only + targeted own-crate `cargo test`), Opus filigree reviewer
+> (adjudication vs pass/kill), main thread = spec, central gates,
+> commits, PR, autonomous resolve + merge after clean CI/reviews.
+
+## P1 — PROBE-WH-MAG (grades E-WH-TWO-SIDES-SIG-CHECKSUM-1 leg 1, [H])
+
+**Question:** does Hadamard-rotating a 4×4 tile's 16-cell magnitude
+vector before i4+i2 quantization reduce reconstruction error vs direct
+i4+i2, as bgz-tensor's row-level result suggests?
+
+- **Home:** `crates/bgz-tensor/src/adaptive_codec.rs` — new `#[cfg(test)]
+  mod probe_wh_mag` (same crate so the private `hadamard_rotate` and the
+  `quantize_f32_to_i4/i2` + dequant helpers are reachable; follow the
+  file's existing test style).
+- **Method:** deterministic synthetic tile fields (seeded SplitMix64-style
+  LCG, NO `rand` dep), 16 cells each, three classes × ≥256 tiles:
+  (a) smooth gradient + rare spike (elevation-like: linear ramp with one
+  cell perturbed 8-32× the ramp step); (b) heavy-tailed spiky (2-3 outlier
+  cells at 10-100× the base scale); (c) uniform noise (control — WH should
+  neither help nor hurt much). For each tile: path A = i4-quantize →
+  dequant → residual → i2-quantize → dequant (the shipped cascade, direct);
+  path B = `hadamard_rotate`(16) first, same cascade, inverse-rotate after
+  (WH is self-inverse up to 1/16 scale — get the scaling right; verify
+  round-trip on an unquantized tile first as a self-check assertion).
+  Metric: per-class mean squared reconstruction error ratio B/A.
+- **Verdict bands (explicit precedence — amended per review, mixed
+  outcomes were uncategorized as first written):** **PASS** if ANY of
+  class (a)/(b) has B/A < 0.9 (WH materially helps where outliers
+  exist); else **KILL** if B/A > 1.1 on ALL classes (WH hurts at 16-cell
+  granularity); else **NEUTRAL** (every remaining combination, including
+  mixed results — record, conjecture stays open, tile-transfer
+  unproven).
+- Print the three ratios in the test output (`--nocapture`-friendly
+  `eprintln!`) AND assert the self-check; the verdict assertion itself is
+  informational (assert only the round-trip identity, not the pass/kill —
+  the Opus reviewer adjudicates the printed numbers so a NEUTRAL result
+  does not red the suite).
+
+## P2 — PROBE-SIG-CHECKSUM (grades leg 2, [S])
+
+**Question:** does the depth-2 truncated signature work as a replayable
+trajectory digest — replay-identical, tree-like edits invisible, non-tree
+perturbations caught?
+
+- **Home:** `crates/jc/src/sig_checksum.rs`, NEW module behind the
+  existing `hambly-lyons` feature (mirror `hambly_lyons.rs`'s structure,
+  thresholds, and `sigker::signature_truncated` usage — READ that file
+  first; reuse its `signature_distance` idea, its DIM/DEPTH constants
+  style, and register nothing in the pillar `prove` list — this is a
+  probe module, not a 12th pillar).
+- **Method:** a deterministic 2-D "trajectory" path of ~64 points (seeded
+  integer walk mapped to f64). Three tests:
+  (a) `replay_identity` — same path built twice → byte-identical
+  signature levels (exact f64 equality is expected — same ops, same
+  order; if that proves flaky use distance < 1e-12);
+  (b) `tree_like_edit_invisible` — insert an A→B→A excursion mid-path →
+  signature distance to the original < the module's zero-threshold
+  (reuse hambly_lyons.rs's forward-leg tolerance);
+  (c) `non_tree_edit_caught` — displace one interior point off the path
+  (a triangle-style detour that does NOT backtrack) → distance > the
+  converse-leg threshold.
+- **PASS:** all three green. **KILL:** (b) or (c) fails at the module's
+  own thresholds (then the digest idea needs depth > 2 or is wrong).
+- Wire `pub mod sig_checksum;` into `crates/jc/src/lib.rs` under the same
+  feature gate style as `hambly_lyons`.
+
+## P3 — PROBE-WALK-SPECTRUM (grades §10(g) anti-confabulation, [H])
+
+**Question:** is the stride-4-mod-17 walk's dependence structure actually
+"known and concentrated" (period-17 harmonics only, no energy at
+palette-lattice periods) vs a PRNG baseline — the measured basis the
+CodeRabbit round demanded for the I-NOISE-FLOOR-JIRAK-friendliness claim?
+
+- **Home:** `crates/helix/src/walk_spectrum.rs`, NEW module (test-only is
+  fine: `#![cfg(test)]`-style or a `#[cfg(test)] mod` in a thin file),
+  using `constants::{MODULUS, STRIDE}`.
+- **Method:** build the ±1 sign sequence s[k] = ±1 from the walk (e.g.
+  parity of the residue `(start + STRIDE·k) mod MODULUS`, N = 4096 =
+  16 × 256 full periods) and a seeded LCG ±1 baseline of equal length.
+  Compute plain circular autocorrelation R(τ) for τ ∈ 1..=512 (O(N·τmax)
+  is fine at this size; NO fft dep). Report: (i) the walk's |R| at
+  multiples of 17 (expected ≈ 1, the known structure); (ii) the walk's
+  |R| at τ ∈ {256, 128, 64, 32, 16} (the palette-lattice periods; note
+  gcd(17, 256) = 1 so expected ≈ noise floor); (iii) the LCG baseline's
+  max |R| over the same τ set.
+- **PASS:** walk lattice-period |R| ≤ 2× the LCG baseline's max |R| AND
+  walk period-17 |R| ≥ 0.9 (dependence is exactly where predicted,
+  nowhere else). **KILL:** walk |R| at any lattice period > 3× baseline
+  (the walk aliases against the palette lattice — §10(g) dies as stated).
+- Same output discipline as P1: print the table, assert only structural
+  sanity (sequence length, ±1 values), reviewer adjudicates.
+
+## Iron rules for this wave
+
+- Sonnet drafters: edit-only + AT MOST their own targeted
+  `cargo test --manifest-path crates/<crate>/Cargo.toml [--features ...]`
+  (bgz-tensor / jc+`--features hambly-lyons` / helix). NO workspace
+  builds, NO worktrees, NO commits, NO new dependencies (no `rand`, no
+  `rustfft` — seeded integer generators and O(N·τ) loops only).
+- No model identifier in file content. `// SAFETY:` n/a (no unsafe —
+  unsafe is BANNED in this wave; if a drafter thinks it needs unsafe,
+  STOP and report).
+- Probes must be deterministic (fixed seeds) and leave the existing test
+  suites green.
+- Main thread runs the central gates: targeted `cargo test` for the three
+  crates + `cargo fmt --check`-equivalent on touched files.
+- Opus filigree reviewer adjudicates printed numbers vs PASS/NEUTRAL/KILL
+  above; verdicts land in EPIPHANIES (prepend) + this plan file's results
+  section + the ndarray matrix-doc §5 probe queue (companion PR).
+- Autonomous merge authority (operator, 2026-07-16 this goal): after CI
+  green + external review comments resolved, the PR is merged by the
+  session (squash/merge per repo default), then the wave continues.
+
+**Reproducibility note (amended per review):** every generator constant
+is pinned IN the probe code, which is the normative source — WH-MAG:
+per-class SplitMix64 seeds in `probe_wh_mag` (`adaptive_codec.rs`);
+SIG-CHECKSUM: the seeded integer walk in `sig_checksum.rs`;
+WALK-SPECTRUM: `WALK_START = 0`, `LCG_SEED = 0x9E37_79B9_7F4A_7C15`,
+PCG multiplier/increment pair, N = 4096, τ_max = 512
+(`walk_spectrum.rs`). The plan intentionally does not duplicate the
+constants; reproduce by running the named test modules.
+
+**LCG-baseline scope note (amended per review):** the P3 "vs baseline"
+comparison is DESCRIPTIVE — the binding evidence for the verdict is the
+closed-form C(τ mod 17) structure (exact integer arithmetic), not a
+statistical significance test; any future significance phrasing must
+derive its threshold via Jirak 2016 weak-dependence rates per
+I-NOISE-FLOOR-JIRAK.
+
+## Results (filled post-run)
+
+Run 2026-07-16 against shipped code (deterministic seeds; Opus reviewer
+adjudicated the printed numbers vs the PASS/NEUTRAL/KILL bands above).
+All three test modules green; the graded probes (P1, P3) assert only
+structural sanity, so a NEUTRAL/KILL verdict does not red the suite
+(P2's asserts are a deterministic identity, correct to assert).
+
+- **PROBE-WH-MAG → NEUTRAL (negative-leaning); [H] bare-tile leg CLOSED
+  NOT-TRANSFERRING.** B/A = gradient+spike 0.929, heavy-tailed 1.317,
+  uniform-noise 1.869 (the probe isolates WH pre-rotation as the only
+  variable — a uniform cascade on both paths, not the shipped I4I2
+  branch). Misses the <0.9 PASS bar everywhere; regresses past 1.1 on
+  (b)+(c); (a) not >1.1 so not a strict KILL → NEUTRAL. WHT₁₆ spreads
+  outlier energy tile-wide, inflating the per-cell quantization floor
+  where the direct cascade got 13-14 near-zero cells for free. The
+  row-level win (E-PALETTE-RESIDUAL-LADDER-1) does not transfer to bare
+  16-cell tiles because the probe has neither the passthrough escape
+  tier nor the centroid residual the shipped row codec pairs WH with;
+  the shipped codec is untouched. Follow-up PROBE-WH-MAG-2 (WH + escape
+  tier + centroid residual) named, deferred to a per-tile-codec
+  consumer.
+- **PROBE-SIG-CHECKSUM → PASS (with a depth-2 blind-spot bound).**
+  replay bit-exact (0.0); tree-like mid-path excursion invisible
+  (0.0 < 1e-9); non-tree interior displacement caught (11.31 > 0.05,
+  level-1 delta 0.0). Caveat: at DEPTH=2 an interior displacement
+  PARALLEL to the neighbor chord is EXACTLY signature-invisible (the
+  signed-area term vanishes) — the digest's null space exceeds
+  tree-like equivalence, so it does NOT catch all non-tree edits. The
+  probe uses a perpendicular offset by design. Mitigable by depth 3 or
+  a paired second digest.
+- **PROBE-WALK-SPECTRUM → KILL (of §10(g)'s "decorrelated by
+  construction" half; period-17-structure half CONFIRMED).** Period-17
+  harmonics |R| = 0.998/0.996/0.994 (R(17m)=1−8m/N). Lattice-period
+  walk |R| max 0.875 (τ=64) vs LCG 0.0205 → 42.7× ≫ 3× KILL bar.
+  R(64) verified: 64 mod 17 = 13, C(13)=C(4)=−15, −15/17 ≈ −0.882 ≈
+  −0.875 — an intrinsic period-17 sidelobe, not lattice aliasing.
+  Coprimality ≠ decorrelation. Corrected claim: the walk gives
+  KNOWN/replayable structure (auditability), NOT low lattice
+  correlation; decorrelation would need a designed low-autocorrelation
+  sequence (Legendre/Paley over p≫17, or an m-sequence). D-QUANTGATE /
+  bijectivity unaffected — only the anti-moiré-in-concept-space
+  consequence dies.
+
+Verdicts: EPIPHANIES `E-H268-PROBE-WAVE-1-RESULTS`; ndarray matrix doc
+§5 results sub-table + §10 re-grades + §10(g) correction (companion PR).