Convert the settings screens/components to Robolectric JVM Compose tests
(umbrella #373, batch 5/9) and drop their globs from
`jacocoNonJvmTestableSurface`, so they count toward JaCoCo's JVM-testable
surface without an emulator.
New `src/test` Robolectric Compose tests (v2 createComposeRule, @Config sdk=36,
NATIVE graphics), mocking each ViewModel where needed:
- SettingsComponentsJvmTest (SectionHeader/SwitchRow/ClickRow/RadioRow/RetentionSection)
- SettingsScreenJvmTest (+ stateless ContactAutocompleteRow)
- AccountSettingsScreenJvmTest
- SignaturesScreenJvmTest
- SignatureEditScreenJvmTest
Line coverage of the newly-included files: SettingsComponents 100%,
SignatureEditScreen 100%, SignaturesScreen 97%, SettingsScreen 95%,
AccountSettingsScreen 84%. Overall scoped line coverage 86.2%. The instrumented
androidTest E2E stay; the JaCoCo floor is unchanged (re-ratchet is #386).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>