feat: broaden CPU and platform coverage across PyPI, nodes, and crate… (#26)

* feat: broaden CPU and platform coverage across PyPI, nodes, and crates.io

Replace static SIMD with runtime CPU-feature dispatch and expand the release
wheel matrix so one set of artifacts runs on any target CPU and platform
without illegal-instruction crashes.

Rust core:
- Add multiversion runtime dispatch (crates/ferro_ta_core/src/simd.rs); drop
  compile-time `wide`. `simd` feature is now default-on and forwarded through
  the pyo3 crate, and stays compatible with #![forbid(unsafe_code)].

Packaging:
- abi3-py310: one cp310-abi3 wheel per platform (covers CPython 3.10+).
- CI matrix adds Linux aarch64 + musllinux (x86_64/aarch64) and Windows arm64.

Node/Docker + docs:
- api/Dockerfile: document baseline+dispatch (no target-cpu pin) and add a
  fail-fast import check; aarch64 containers now install cleanly.
- Rewrite docs/guides/simd.md; fix stale `wide` mention in ADR 0003.
- Add ADR 0006 (CPU coverage strategy).

Also bundles in-flight release prep already staged in the tree (DTW exception
types, SBOM/provenance security, supporting docs).

* fix(ci): clear cargo-deny and pip-audit failures; apply dependency bumps

cargo-deny (advisories):
- Ignore pyo3 RUSTSEC-2026-0176 / RUSTSEC-2026-0177 in deny.toml with a
  documented rationale: ferro-ta uses neither affected code path
  (PyList/PyTuple nth iterators; PyCFunction::new_closure). Upstream fix
  needs pyo3 >=0.29 (large API migration), tracked as a follow-up.

pip-audit:
- Bump dev lockfile idna 3.18, pytest 9.1.1, urllib3 2.7.0 to clear
  PYSEC-2026-215, CVE-2025-71176, PYSEC-2026-141/142.

Dependency bumps (supersede open dependabot PRs; they auto-close on merge):
- cargo: log 0.4.32, serde_json 1.0.150, rayon 1.12.0
- api/requirements.txt: uvicorn>=0.49.0, pydantic>=2.13.4, ferro-ta>=1.1.4
- CI actions: deploy-pages v5, upload-pages-artifact v5, action-gh-release v3

The open `wide` 1.5.0 bump (PR #24) is obsolete — the crate is removed in
this branch.

* chore: address CodeRabbit review; remove docs/adr section

CodeRabbit findings:
- CI sbom job: add `attestations: write` so attest-build-provenance can run
  (it had only contents:write + id-token:write).
- simd.rs: vectorize `wma_seed` with lane-local accumulators — it was scalar
  behind the multiversion wrapper, adding dispatch overhead for no SIMD gain.
- CHANGELOG: consolidate the duplicate `### Changed` heading.
- python/ferro_ta/__init__.py: also re-export the `FerroTaError` alias.
- docs/guides/dtw.md: soften "byte-for-byte" parity to within-tolerance.

Remove docs/adr/ at maintainer request and clean up the ADR links in the
SIMD and DTW guides. The ADR files remain in commit 9506a30 if ever needed.

crates/ferro_ta_core/src/statistic.rs

@@ -449,6 +449,36 @@ mod tests {
         assert!((d1 - d2).abs() < 1e-12);
     }
 
+    #[test]
+    fn dtw_nan_in_input_propagates() {
+        // NaN in either input must propagate to the distance (IEEE 754 semantics).
+        let a = vec![1.0, 2.0, f64::NAN, 4.0];
+        let b = vec![1.0, 2.0, 3.0, 4.0];
+        assert!(dtw_distance(&a, &b, None).is_nan());
+        assert!(dtw_distance(&b, &a, None).is_nan());
+    }
+
+    #[test]
+    fn dtw_is_symmetric() {
+        let a = vec![1.0, 4.0, 2.0, 8.0, 3.0, 6.0, 5.0];
+        let b = vec![2.0, 3.0, 7.0, 4.0, 5.0, 1.0, 9.0];
+        let d_ab = dtw_distance(&a, &b, None);
+        let d_ba = dtw_distance(&b, &a, None);
+        assert!((d_ab - d_ba).abs() < 1e-12);
+    }
+
+    #[test]
+    fn dtw_path_length_bounded() {
+        // A valid warp path has length between max(n, m) and n + m - 1.
+        let a: Vec<f64> = (0..7).map(|x| x as f64).collect();
+        let b: Vec<f64> = (0..10).map(|x| (x as f64).sin()).collect();
+        let (_, path) = dtw_path(&a, &b, None);
+        let n = a.len();
+        let m = b.len();
+        assert!(path.len() >= n.max(m));
+        assert!(path.len() <= n + m - 1);
+    }
+
     #[test]
     fn dtw_window_constrained_ge_unconstrained() {
         // window convention matches dtaidistance: Some(w) means |i-j| < w.