Fix infinite loop and memory leak in DockTilePlugin

The ghosttyAppPath property searched for hardcoded "Ghostty.app" in the
bundle path, but the app is named "Ghostree.app". The loop walked past
root where URL.deletingLastPathComponent() appends "/.." indefinitely,
causing unbounded memory growth in the Dock Extra process even when the
app is not running.

Match by .app path extension instead of hardcoded name.

Author: nicosuave

macos/Sources/Features/Custom App Icon/DockTilePlugin.swift

@@ -20,11 +20,11 @@ class DockTilePlugin: NSObject, NSDockTilePlugIn {
 
     private var iconChangeObserver: Any?
 
-    /// The path to the Ghostty.app, determined based on the bundle path of this plugin.
+    /// The path to the host .app bundle, determined based on the bundle path of this plugin.
     var ghosttyAppPath: String {
         var url = pluginBundle.bundleURL
-        // Remove "/Contents/PlugIns/DockTilePlugIn.bundle" from the bundle URL to reach Ghostty.app.
-        while url.lastPathComponent != "Ghostty.app", !url.lastPathComponent.isEmpty {
+        // Walk up from "*.app/Contents/PlugIns/DockTilePlugin.plugin" to reach the .app bundle.
+        while url.pathExtension != "app", url.path != "/" {
             url.deleteLastPathComponent()
         }
         return url.path