Use BuildConfig for version display in About section

Replace hardcoded version string with BuildConfig.VERSION_NAME so
the About screen always reflects the version from build.gradle.kts.

app/build.gradle.kts

@@ -60,6 +60,7 @@ android {
     }
     buildFeatures {
         compose = true
+        buildConfig = true
     }
     packaging {
         resources {

app/src/main/java/cz/bugsy/karemote/ui/screens/settings/SettingsScreen.kt

@@ -206,7 +206,7 @@ fun SettingsScreen(
                 )
                 Spacer(modifier = Modifier.height(4.dp))
                 Text(
-                    text = "Version 1.0",
+                    text = "Version ${cz.bugsy.karemote.BuildConfig.VERSION_NAME}",
                     style = MaterialTheme.typography.bodySmall,
                     color = MaterialTheme.colorScheme.onSurfaceVariant
                 )