Replace Skip implementation with Kotlin Multiplatform implementation

shared/src/jvmMain/kotlin/xyz/tyiu/satsprice/Platform.jvm.kt

@@ -0,0 +1,7 @@
+package xyz.tyiu.satsprice
+
+class JVMPlatform : Platform {
+    override val name: String = "Java ${System.getProperty("java.version")}"
+}
+
+actual fun getPlatform(): Platform = JVMPlatform()

shared/src/jvmMain/kotlin/xyz/tyiu/satsprice/SystemCurrencies.jvm.kt

@@ -0,0 +1,21 @@
+package xyz.tyiu.satsprice
+
+import java.util.Currency
+import java.util.Locale
+
+actual fun systemCurrencies(): List<CurrencyInfo> =
+    Currency.getAvailableCurrencies()
+        .map { CurrencyInfo(it.currencyCode, it.getDisplayName(Locale.getDefault())) }
+        .sortedBy { it.code }
+
+actual fun localeCurrencyCode(): String? = try {
+    Currency.getInstance(Locale.getDefault())?.currencyCode
+} catch (e: IllegalArgumentException) {
+    null
+}
+
+actual fun currencyDecimalDigits(code: String): Int = try {
+    Currency.getInstance(code).defaultFractionDigits.takeIf { it >= 0 } ?: 2
+} catch (e: IllegalArgumentException) {
+    2
+}

shared/src/jvmMain/kotlin/xyz/tyiu/satsprice/ui/Dimensions.jvm.kt

@@ -0,0 +1,6 @@
+package xyz.tyiu.satsprice.ui
+
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+
+actual val screenHorizontalPadding: Dp = 24.dp