fix: enforce only one instance of the app

src-tauri/Cargo.lock

@@ -108,6 +108,7 @@ dependencies = [
  "tauri-plugin-log",
  "tauri-plugin-notification",
  "tauri-plugin-os",
+ "tauri-plugin-single-instance",
  "tauri-plugin-updater",
  "thiserror 2.0.12",
  "tokio",
@@ -4846,6 +4847,21 @@ dependencies = [
  "thiserror 2.0.12",
 ]
 
+[[package]]
+name = "tauri-plugin-single-instance"
+version = "2.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1320af4d866a7fb5f5721d299d14d0dd9e4e6bc0359ff3e263124a2bf6814efa"
+dependencies = [
+ "serde",
+ "serde_json",
+ "tauri",
+ "thiserror 2.0.12",
+ "tracing",
+ "windows-sys 0.59.0",
+ "zbus",
+]
+
 [[package]]
 name = "tauri-plugin-updater"
 version = "2.7.0"