fix(single-instance): explicitly D-Bus name replacement

.changes/single-instance-dbus-name.md

@@ -0,0 +1,6 @@
+---
+"single-instance": patch
+---
+
+Fix D-Bus name replacement logic on Linux to prevent multiple instances from acquiring the same well-known name.  
+This patch updates the `zbus` dependency to the latest compatible version (`^5.9`) and explicitly sets `RequestNameFlags` to ensure a second instance fails to acquire the D-Bus name when another one is already running.

Cargo.toml

@@ -23,7 +23,7 @@ schemars = "0.8"
 dunce = "1"
 specta = "^2.0.0-rc.16"
 glob = "0.3"
-zbus = "5"
+zbus = "5.9"
 
 [workspace.package]
 edition = "2021"

plugins/single-instance/src/platform_impl/linux.rs

@@ -61,6 +61,8 @@ pub fn init<R: Runtime>(f: Box<SingleInstanceCallback<R>>) -> TauriPlugin<R> {
                 .unwrap()
                 .name(dbus_name.as_str())
                 .unwrap()
+                .replace_existing_names(false)
+                .allow_name_replacements(false)
                 .serve_at(dbus_path.as_str(), single_instance_dbus)
                 .unwrap()
                 .build()