chore: add changeset for configurable PII entity types

Author: yjouini

.changeset/sweet-comics-sing.md

@@ -0,0 +1,11 @@
+---
+"kiji-privacy-proxy": minor
+---
+
+Configurable PII entity types and custom regex patterns
+
+- Chrome extension options page: enable/disable PII entity types per-request
+- Custom regex patterns: add/edit/remove user-defined regex rules with replacement text
+- New API endpoints: `GET /api/pii/labels`, `GET/POST /api/pii/patterns`, `PUT/DELETE /api/pii/patterns/{id}`
+- Backend `MaskText` accepts `enabled_labels` to filter which PII types are masked
+- Entity deduplication: overlapping spans resolved by length, custom regex wins ties