Build native UI shell foundation

shared/src/jvmMain/kotlin/com/vnidrop/app/logging/PlatformLogStore.jvm.kt

@@ -0,0 +1,56 @@
+package com.vnidrop.app.logging
+
+import java.io.File
+import java.nio.charset.StandardCharsets
+
+actual fun createPlatformLogStore(appDataDir: String, policy: LogRotationPolicy): PlatformLogStore =
+	JvmPlatformLogStore(appDataDir, policy)
+
+actual fun platformNowMillis(): Long = System.currentTimeMillis()
+
+private class JvmPlatformLogStore(
+	appDataDir: String,
+	private val policy: LogRotationPolicy,
+) : PlatformLogStore {
+	private val directory = File(appDataDir, "logs")
+	private val activeFile = File(directory, "app.log")
+
+	override val logDirectory: String = directory.absolutePath
+
+	@Synchronized
+	override fun append(line: String) {
+		directory.mkdirs()
+		val bytes = line.toByteArray(StandardCharsets.UTF_8)
+		if (policy.shouldRotate(activeFile.length(), bytes.size.toLong())) {
+			rotate()
+		}
+		activeFile.appendBytes(bytes)
+	}
+
+	@Synchronized
+	override fun listLogFiles(): List<LogFileInfo> {
+		directory.mkdirs()
+		return directory
+			.listFiles { file -> file.isFile && file.name.startsWith("app") && file.name.endsWith(".log") }
+			.orEmpty()
+			.sortedByDescending { it.lastModified() }
+			.map { file -> LogFileInfo(file.name, file.absolutePath, file.length(), file.lastModified()) }
+	}
+
+	private fun rotate() {
+		if (policy.maxFiles == 0) {
+			activeFile.delete()
+			return
+		}
+		File(directory, "app.${policy.maxFiles}.log").delete()
+		for (index in policy.maxFiles - 1 downTo 1) {
+			val source = File(directory, "app.$index.log")
+			if (source.exists()) {
+				source.renameTo(File(directory, "app.${index + 1}.log"))
+			}
+		}
+		if (activeFile.exists()) {
+			activeFile.renameTo(File(directory, "app.1.log"))
+		}
+	}
+}

shared/src/jvmMain/kotlin/com/vnidrop/app/platform/PlatformSystemAppearance.jvm.kt

@@ -0,0 +1,51 @@
+package com.vnidrop.app.platform
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.SideEffect
+import java.awt.Color
+import java.awt.EventQueue
+import java.awt.Window
+import javax.swing.JFrame
+
+@Composable
+actual fun PlatformSystemAppearance(isDarkTheme: Boolean) {
+	SideEffect {
+		DesktopSystemAppearance.apply(isDarkTheme)
+	}
+}
+
+internal object DesktopSystemAppearance {
+	private const val MAC_APPEARANCE_PROPERTY = "apple.awt.application.appearance"
+	private const val TRANSPARENT_TITLE_BAR_PROPERTY = "apple.awt.transparentTitleBar"
+
+	fun apply(isDarkTheme: Boolean) {
+		if (!isMacOs()) return
+		System.setProperty(MAC_APPEARANCE_PROPERTY, macOsAppearanceName(isDarkTheme))
+		EventQueue.invokeLater {
+			Window.getWindows().forEach { window ->
+				applyWindowChrome(window, isDarkTheme)
+			}
+		}
+	}
+
+	internal fun macOsAppearanceName(isDarkTheme: Boolean): String =
+		if (isDarkTheme) "NSAppearanceNameDarkAqua" else "NSAppearanceNameAqua"
+
+	internal fun titlebarBackground(isDarkTheme: Boolean): Color =
+		if (isDarkTheme) Color(0x12, 0x12, 0x12) else Color(0xF8, 0xF8, 0xF8)
+
+	private fun applyWindowChrome(window: Window, isDarkTheme: Boolean) {
+		val background = titlebarBackground(isDarkTheme)
+		window.background = background
+		(window as? JFrame)?.rootPane?.let { rootPane ->
+			// Keep the native macOS controls and drag behavior, but let the
+			// decorated titlebar blend with the app's resolved light/dark surface.
+			rootPane.putClientProperty(TRANSPARENT_TITLE_BAR_PROPERTY, true)
+			rootPane.background = background
+			rootPane.contentPane.background = background
+		}
+	}
+
+	private fun isMacOs(): Boolean =
+		System.getProperty("os.name").startsWith("Mac", ignoreCase = true)
+}