v4.0.0 of bdaya_shared_value

A straightforward way to manage global state in flutter apps. Changelog excerpt: ### ⚠ BREAKING CHANGES - Minimum Dart SDK raised to >=3.8.0 (Dart 3 required). - Minimum Flutter SDK raised to >=3.32.0. - Upgraded rxdart to >=0.28.0 <2.0.0 (unblocks package:oidc rxdart 0.28 upgrade). - Upgraded shared_preferences to ^2.5.0. ### Features - Comprehensive test suite (24 tests) covering SharedValue API, streams, persistence, custom encode/decode, widgets, and InheritedModel. - CI pipeline via GitHub Actions (stable + beta Flutter channels). - Automated pub.dev publishing via t[...]