fix(verify): repoint wrapper to archive/v1 paths (#559) + cross-platform FFT probe (#560)

#559: Fix ./verify wrapper

The repo moved v1/ -> archive/v1/ but ./verify still pointed at the old
paths and failed before reaching the proof script with:
  FAIL: Reference signal not found at .../v1/data/proof/sample_csi_data.json
  FAIL: verify.py not found at .../v1/data/proof/verify.py

Update PROOF_DIR, V1_SRC, and two diagnostic strings to use archive/v1/.

#560: Add platform probe + root-cause evidence

Add scripts/probe-fft-platform.py that runs verify.py's hash-relevant
scipy.fft.fft / scipy.signal.windows.hamming calls in isolation on a
deterministic input (no pydantic Settings stack), so the source of
divergence can be located across platforms.

Tested on three machines via Tailscale:

  Windows (Intel AVX-512, numpy 2.4.2 / scipy 1.17.1):
    first4_psd_floats = [..., 94.40426770856882, ..., 51.677496924642476]
    sha256 = 78b3fb4acb8cc18c3e870f92e29ee98143c7cac4767f2f71b0fc384a82b92f6e

  ruvultra (Linux x86_64, numpy 1.26.4 / scipy 1.14.1):
    first4_psd_floats = [..., 94.40426770856882, ..., 51.677496924642476]
    sha256 = 41dc56416b6e8346d6457b1e3c9ca5d4b9035f645658e40e2eb668d08efaf9b6

  ruv-mac-mini (Apple Silicon arm64/NEON, numpy 2.4.4 / scipy 1.17.1):
    first4_psd_floats = [..., 94.4042677085688, ..., 51.67749692464246]
    sha256 = 9b5e192b56d26a486eefe5dff6bb0e05f6223163a4246043fc168002d495efca

Win and Linux agree on the first PSD/doppler values but produce
different SHA-256s (later FFT bins diverge due to scipy version's
pocketfft SIMD path). Mac arm64 differs from x86_64 at ULP precision
(~2e-14 at value ~94 = ~1 ULP) on index 1 of the FIRST PSD bins.

Root cause: SIMD-vectorized FFT reorders floating-point operations.
NEON on Apple Silicon vs AVX2/AVX-512 on x86_64 produce ULP-different
results, which a bit-exact SHA-256 cannot tolerate. The verify.py
docstring at line 172 ("platform-independent for IEEE 754 compliant
systems") is incorrect -- IEEE 754 guarantees per-operation
determinism but vectorized FFT reorders ops.

This commit ships the diagnostic probe + the #559 path fix only. The
verify.py hash function itself (quantize-before-hash to absorb ULP
divergence + regeneration of expected_features.sha256 on a canonical
CI platform) is a follow-up that affects a published trust-anchor
artifact -- left for maintainer decision.

Verification:
  cd <repo> && ./verify
  # before: FAIL before reaching pipeline (v1/... not found)
  # after:  reaches verify.py and runs the pipeline

  python3 scripts/probe-fft-platform.py
  # prints JSON with sha256 + first-few-floats per platform

Refs: #559, #560

Co-Authored-By: claude-flow <ruv@ruv.net>

verify

@@ -19,9 +19,9 @@
 set -euo pipefail
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-PROOF_DIR="${SCRIPT_DIR}/v1/data/proof"
+PROOF_DIR="${SCRIPT_DIR}/archive/v1/data/proof"
 VERIFY_PY="${PROOF_DIR}/verify.py"
-V1_SRC="${SCRIPT_DIR}/v1/src"
+V1_SRC="${SCRIPT_DIR}/archive/v1/src"
 
 # Colors (disabled if not a terminal)
 if [ -t 1 ]; then
@@ -136,7 +136,7 @@ echo ""
 echo -e "${CYAN}[PHASE 3] PRODUCTION CODE INTEGRITY SCAN${RESET}"
 echo ""
 echo "  Scanning ${V1_SRC} for np.random.rand / np.random.randn calls..."
-echo "  (Excluding v1/src/testing/ -- test helpers are allowed to use random.)"
+echo "  (Excluding archive/v1/src/testing/ -- test helpers are allowed to use random.)"
 echo ""
 
 MOCK_FINDINGS=0
@@ -204,7 +204,7 @@ elif [ $PIPELINE_EXIT -eq 2 ]; then
     echo -e "  ${YELLOW}${BOLD}RESULT: SKIP${RESET}"
     echo ""
     echo "  No expected hash file to compare against."
-    echo "  Run: python v1/data/proof/verify.py --generate-hash"
+    echo "  Run: python archive/v1/data/proof/verify.py --generate-hash"
     echo ""
     echo -e "${BOLD}======================================================================${RESET}"
     exit 2