docs(system-tray): remove SingleInstanceManager (pending deprecation)

Author: kdroidFilter

docs/runtime/system-tray/index.md

@@ -20,7 +20,6 @@ Where the standard Java `SystemTray` gives you a pixelated icon and a crude AWT
 | Checkable items | Not available | Native checkable items |
 | Primary action (left-click) | Not available | Per-platform behavior |
 | Tray position detection | Not available | Built-in, for window positioning |
-| Single instance | Not available | Built-in with restore callback |
 | Popup window | Not available | `TrayApp` — Compose window anchored to tray |
 
 ## Quick example
@@ -62,4 +61,4 @@ dependencies {
 - [Tray API](tray-api.md) — `Tray()` composable, icon types, primary actions, platform-specific icons
 - [Menu DSL](menu-dsl.md) — Items, checkable items, submenus, dividers, icons in menus
 - [TrayApp](tray-app.md) — Popup window anchored to the tray icon
-- [Utilities](utilities.md) — Single instance management, tray position detection, dark mode detection
+- [Utilities](utilities.md) — Tray position detection, dark mode detection

docs/runtime/system-tray/utilities.md

@@ -2,57 +2,6 @@
 
 ComposeNativeTray includes several utilities that are essential for tray-based applications.
 
-## Single Instance Manager
-
-Most tray apps should only run one instance. `SingleInstanceManager` enforces this and lets the second launch restore the existing window:
-
-```kotlin
-fun main() {
-    val isSingleInstance = SingleInstanceManager.isSingleInstance(
-        onRestoreRequest = {
-            // Called when another instance tries to start
-            isWindowVisible = true
-        }
-    )
-
-    if (!isSingleInstance) {
-        // Another instance is already running — it received the restore request
-        return
-    }
-
-    application {
-        // Your app...
-    }
-}
-```
-
-### Custom configuration
-
-```kotlin
-SingleInstanceManager.configuration = SingleInstanceManager.Configuration(
-    lockDirectory = Path("/custom/lock/dir"),
-    appIdentifier = "com.example.myapp",
-)
-```
-
-### Data passing between instances
-
-The new instance can write data to a temporary file that the existing instance reads:
-
-```kotlin
-val isSingleInstance = SingleInstanceManager.isSingleInstance(
-    onRestoreFileCreated = { path ->
-        // New instance writes data here
-        path.writeText("open-file:/path/to/file.txt")
-    },
-    onRestoreRequest = { path ->
-        // Existing instance reads it
-        val data = path.readText()
-        handleDeepLink(data)
-    }
-)
-```
-
 ## Tray Position Detection
 
 Position a window next to the tray icon — essential for `TrayApp`-style popup windows: