Issue #190 field-test build
This prerelease adds independent locked-filter persistence for Library Browse, Local Books, Series, Smart Scope, and genre-specific Series contexts.
Enable Lock filter in a filter sheet to restore that screen and scope's filter across navigation and app sessions. The existing default filter and Last read sorting are unchanged.
Verification: JVM tests, lint, debug APK assembly, and Android-test APK assembly passed. The implementation was also user-confirmed working on-device.
This is a debug field-test build, not a production release.