3.0.0-alpha04

Breaking change: legacy Android DataStore/SharedPreferences helpers were
replaced by the multiplatform preferences API.

What's new

• Added KMP JchuPreferences implementations backed by DataStore on Android
  and UserDefaults on iOS.
• Added typed preference keys, tests and dedicated preferences documentation.
• Added a shared network Failure model and throwable-to-failure mapping.

Improvements

• Unified network resources and failures under stable models packages.
• Improved HTTP status classification and network error conversion.
• Simplified the preferences artifact and its platform-specific setup.

Fixes

• Corrected network failure propagation in NetworkBoundResource.
• Removed obsolete preference manifests, ProGuard rules and legacy helpers
  that could conflict with the KMP implementation.