3.0.0 RN update

Author: kwart

distribution/doc/release-notes/3.0.0.md

@@ -29,6 +29,8 @@ packaging.
 - New and updated translations (Czech, German, French, Spanish, Slovak,
   Portuguese, Croatian, Simplified Chinese, Traditional Chinese, and
   more — thanks to all Weblate contributors).
+- Translation bundles (`messages*.properties`) are now stored in UTF-8,
+  simplifying contributions in non-Latin scripts.
 - Per-version release notes files are now attached as the GitHub
   Release body.
 - User guide restructured around the new JavaFX UI, with a shared
@@ -37,6 +39,9 @@ packaging.
 - Improved symlink handling, including macOS (#168).
 - Integration tests added for the PDF signing pipeline (#293).
 - Moved publishing from OSSRH to Maven Central.
+- Migrated the PDF engine from the legacy OpenPDF 1.x line
+  (`com.lowagie.text.*`) to OpenPDF 3 (`org.openpdf.text.*`), updated
+  PDFBox to 3.0.7, and bumped BouncyCastle to 1.84.
 - Numerous dependency and GitHub Actions updates.
 
 Thanks to everyone who contributed code, translations, bug reports,