fix(macOS): write tray state to writable tmp and namespace by app ID to avoid conflicts

- Persist tray_position.properties to: {java.io.tmpdir}/ComposeNativeTray/<appId>/tray_position.properties
- Update SingleInstanceManager to use AppIdProvider for lock/restore files
- Backward-compatible reads from legacy CWD and old tmp locations
- Resilient I/O (swallow exceptions) to avoid crashes on read-only filesystems

Author: kdroidFilter

src/commonMain/kotlin/com/kdroid/composetray/utils/AppId.kt

@@ -0,0 +1,37 @@
+package com.kdroid.composetray.utils
+
+/**
+ * Provides a unique, stable application identifier to namespace shared resources
+ * (temp files, locks, properties) and avoid conflicts when multiple apps use
+ * this library on the same machine.
+ *
+ * Resolution order (first non-empty wins):
+ * 1) System property "compose.native.tray.appId"
+ * 2) Environment variable "COMPOSE_NATIVE_TRAY_APP_ID"
+ * 3) Main class from system property "sun.java.command" (first token)
+ * 4) Fallback to "ComposeNativeTrayApp"
+ */
+object AppIdProvider {
+    private val cached by lazy { computeAppId() }
+
+    fun appId(): String = cached
+
+    private fun computeAppId(): String {
+        val sunCmd = System.getProperty("sun.java.command")?.trim().orEmpty()
+        println("AppIdProvider: sunCmd: $sunCmd")
+
+        if (sunCmd.isNotEmpty()) {
+            val firstToken = sunCmd.split(" ", limit = 2).firstOrNull().orEmpty()
+            if (firstToken.isNotEmpty()) return sanitize(firstToken)
+        }
+
+        // Fallback
+        return "ComposeNativeTrayApp"
+    }
+
+    private fun sanitize(raw: String): String {
+        // Replace non-alphanumeric/._- with underscore; trim length if excessively long
+        val cleaned = raw.replace(Regex("[^A-Za-z0-9._-]"), "_")
+        return cleaned.take(128).ifEmpty { "ComposeNativeTrayApp" }
+    }
+}

src/commonMain/kotlin/com/kdroid/composetray/utils/SingleInstanceManager.kt

@@ -166,7 +166,7 @@ object SingleInstanceManager {
     }
 
     private fun getAppIdentifier(): String {
-        val callerClassName = Thread.currentThread().stackTrace[3].className
-        return callerClassName.replace(".", "_")
+        // Use unified app ID provider to avoid cross-app conflicts and allow explicit override
+        return AppIdProvider.appId()
     }
 }

src/commonMain/kotlin/com/kdroid/composetray/utils/TrayPosition.kt

@@ -60,38 +60,70 @@ private const val POSITION_KEY = "TrayPosition"
 private const val X_KEY = "TrayX"
 private const val Y_KEY = "TrayY"
 
+// Use a writable tmp/cache directory to avoid read-only filesystem issues (e.g., macOS app bundle working dir)
+private fun trayPropertiesFile(): File {
+    val tmpBase = System.getProperty("java.io.tmpdir") ?: "."
+    val appDir = File(File(tmpBase, "ComposeNativeTray"), AppIdProvider.appId())
+    // Best-effort create directory; if it fails, we will fallback to legacy file access patterns safely
+    runCatching { if (!appDir.exists()) appDir.mkdirs() }.onFailure { /* ignore */ }
+    return File(appDir, PROPERTIES_FILE)
+}
+
+// Legacy properties file in working directory (for backward compatibility)
+private fun legacyPropertiesFile(): File = File(PROPERTIES_FILE)
+
+// Previous tmp location before appId namespacing (for backward-compatible reads only)
+private fun oldTmpPropertiesFile(): File {
+    val tmpBase = System.getProperty("java.io.tmpdir") ?: "."
+    val oldDir = File(tmpBase, "ComposeNativeTray")
+    return File(oldDir, PROPERTIES_FILE)
+}
+
+private fun loadPropertiesFrom(file: File): Properties? {
+    if (!file.exists()) return null
+    return runCatching {
+        Properties().apply { file.inputStream().use { load(it) } }
+    }.getOrNull()
+}
+
+private fun storePropertiesTo(file: File, props: Properties) {
+    // Ensure parent exists if any
+    file.parentFile?.let { runCatching { if (!it.exists()) it.mkdirs() } }
+    runCatching { file.outputStream().use { props.store(it, null) } }
+    // We intentionally swallow exceptions to avoid crashing if the FS is read-only
+}
+
 internal fun saveTrayPosition(position: TrayPosition) {
-    val properties = Properties()
-    val file = File(PROPERTIES_FILE)
-    if (file.exists()) {
-        properties.load(file.inputStream())
-    }
+    val preferredFile = trayPropertiesFile()
+    val properties = loadPropertiesFrom(preferredFile)
+        ?: loadPropertiesFrom(oldTmpPropertiesFile())
+        ?: loadPropertiesFrom(legacyPropertiesFile())
+        ?: Properties()
     properties.setProperty(POSITION_KEY, position.name)
-    file.outputStream().use { properties.store(it, null) }
+    storePropertiesTo(preferredFile, properties)
 }
 
 internal fun saveTrayClickPosition(x: Int, y: Int, position: TrayPosition) {
-    val properties = Properties()
-    val file = File(PROPERTIES_FILE)
-    if (file.exists()) {
-        properties.load(file.inputStream())
-    }
+    val preferredFile = trayPropertiesFile()
+    val properties = loadPropertiesFrom(preferredFile)
+        ?: loadPropertiesFrom(oldTmpPropertiesFile())
+        ?: loadPropertiesFrom(legacyPropertiesFile())
+        ?: Properties()
     properties.setProperty(POSITION_KEY, position.name)
     properties.setProperty(X_KEY, x.toString())
     properties.setProperty(Y_KEY, y.toString())
-    file.outputStream().use { properties.store(it, null) }
+    storePropertiesTo(preferredFile, properties)
 }
 
 internal fun loadTrayClickPosition(): TrayClickPosition? {
-    val file = File(PROPERTIES_FILE)
-    if (!file.exists()) return null
-
-    val properties = Properties()
-    properties.load(file.inputStream())
+    // Prefer new location, fallback to old tmp location, then legacy working dir
+    val props = loadPropertiesFrom(trayPropertiesFile())
+        ?: loadPropertiesFrom(oldTmpPropertiesFile())
+        ?: loadPropertiesFrom(legacyPropertiesFile()) ?: return null
 
-    val positionStr = properties.getProperty(POSITION_KEY) ?: return null
-    val x = properties.getProperty(X_KEY)?.toIntOrNull() ?: return null
-    val y = properties.getProperty(Y_KEY)?.toIntOrNull() ?: return null
+    val positionStr = props.getProperty(POSITION_KEY) ?: return null
+    val x = props.getProperty(X_KEY)?.toIntOrNull() ?: return null
+    val y = props.getProperty(Y_KEY)?.toIntOrNull() ?: return null
 
     return try {
         TrayClickPosition(x, y, TrayPosition.valueOf(positionStr))
@@ -150,11 +182,11 @@ fun getTrayPosition(): TrayPosition {
             }
 
             // Legacy fallback - just position without coordinates
-            val properties = Properties()
-            val file = File(PROPERTIES_FILE)
-            if (file.exists()) {
-                properties.load(file.inputStream())
-                val position = properties.getProperty(POSITION_KEY, null)
+            run {
+                val props = loadPropertiesFrom(trayPropertiesFile())
+                    ?: loadPropertiesFrom(oldTmpPropertiesFile())
+                    ?: loadPropertiesFrom(legacyPropertiesFile())
+                val position = props?.getProperty(POSITION_KEY, null)
                 if (position != null) {
                     return try {
                         TrayPosition.valueOf(position)