v2.3.0 — Multilingual PDF report, perio/odontogram sync

See CHANGELOG.md [2.3.0] for full details.

Highlights:

• Multilingual PDF report: bundled Unicode fonts (Latin/Cyrillic + lazy-loaded Arabic & Chinese) so every UI language renders correctly, colour themes, grouped dentition-summary table, computed age, footer.
• Periodontal chart now syncs with the odontogram: missing teeth draw no crown, primary teeth use deciduous artwork; tooth-spacing distortion fixed.
• Dynamic perio abbreviation glossary; findings/implants layout cleanup.
• Dev: ESLint config usable again (ignores dist/docs), dead code removed.