Release polish: trim HF front-matter, add CODE_OF_CONDUCT, prune duplicate tests

Rename output/ -> outputs/; add docs/CHANGELOG.md

Refactor to Gold-RAP structure: src/ package, tests/, docs/, data/, output/

Only mask date-of-birth (not visit dates); readable redaction labels

Backport v0-base UK entity recognizers: NINO, passport, vehicle reg, comma-form NHS

Consolidate into NoteGuard: fold the Presidio gate into the noteguard spine

Add NHS de-identification gate (Presidio + spaCy)