refactor(commons): migrate from Moko to Compose Multiplatform Resources

Remove Moko Resources dependency that blocks AGP 9.0 migration.
Migrate to built-in Compose Multiplatform Resources which is compatible
with the new KMP Android plugin.

- Remove moko-resources plugin and libraries from commons module
- Move strings.xml from moko-resources/ to composeResources/values/
- Update imports from SharedRes.strings.* to Res.string.*
- Add compose.components.resources dependency to desktopApp
- Configure resource package as com.vitorpamplona.amethyst.commons.resources

Closes #1675

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

desktopApp/build.gradle.kts

@@ -25,6 +25,7 @@ dependencies {
     implementation(compose.desktop.currentOs)
     implementation(compose.material3)
     implementation(compose.materialIconsExtended)
+    implementation(compose.components.resources)
 
     // Quartz Nostr library (will use JVM target)
     implementation(project(":quartz"))