v0.5.2 — pin onnx-community NER SHA + promote adopter assets

[0.5.2] - 2026-04-29

Added

• NER adopter assets (todo #301, GH issue #90 items 1+4): promoted the
  Davlan mBERT label contract and canonical NER policy snippet to
  assets/ner/ for framework adapters and adopters. assets/ner/README.md
  documents the BIO tag to Gaze class schema, the "drop" sentinel, and the
  future gaze model fetch <name> / gaze policy snippet ner manifest path.

Changed

• Pinned default NER artifact source (todo #292, GH issue #90 item 2):
  `scripts/fetch-ner-model.sh` now installs the pre-quantized int8 ONNX artifact
  from `onnx-community/bert-base-multilingual-cased-ner-hrl-ONNX` at commit
  `cfe67b1c1c4c91c1b26ac192955fc0971e62d8c8`, copies the Gaze-authored
  `labels.json` contract, and verifies all installed bytes against the
  repository-root `SHA256SUMS`.
• Policy docs for NER adopters: `docs/policy.md` now cites the canonical
  `assets/ner/` contracts, documents `[ner].locale` as a single BCP47 string,
  and calls out Rust-regex inline flags such as `(?i)` in
  `[[policy.custom_recognizers]].pattern`.

---

PR: #94 (squash-merge 4776ff49)
Closes: #292, #301, GH issue #90 items 1+2+4

Adapter critical path: gaze-laravel BinaryInstaller::PINNED_VERSION → 0.5.2.