feat(tauri): add plugin_boxed methods (#13837)

* feat(tauri): add `plugin_dyn` methods

* refactor: rename `plugin_dyn` to `plugin_boxed`

Author: WSH032

.changes/plugin-boxed.md

@@ -0,0 +1,5 @@
+---
+tauri: "minor:enhance"
+---
+
+Add `AppHandle::plugin_boxed` and `Builder::plugin_boxed` methods to allow adding plugins in the form of boxed trait objects.

crates/tauri/src/app.rs

@@ -484,10 +484,16 @@ impl<R: Runtime> AppHandle<R> {
   ///     Ok(())
   ///   });
   /// ```
-  #[cfg_attr(feature = "tracing", tracing::instrument(name = "app::plugin::register", skip(plugin), fields(name = plugin.name())))]
   pub fn plugin<P: Plugin<R> + 'static>(&self, plugin: P) -> crate::Result<()> {
-    let mut plugin = Box::new(plugin) as Box<dyn Plugin<R>>;
+    self.plugin_boxed(Box::new(plugin))
+  }
 
+  /// Adds a Tauri application plugin.
+  ///
+  /// This method is similar to [`Self::plugin`],
+  /// but accepts a boxed trait object instead of a generic type.
+  #[cfg_attr(feature = "tracing", tracing::instrument(name = "app::plugin::register", skip(plugin), fields(name = plugin.name())))]
+  pub fn plugin_boxed(&self, mut plugin: Box<dyn Plugin<R>>) -> crate::Result<()> {
     let mut store = self.manager().plugins.lock().unwrap();
     store.initialize(&mut plugin, self, &self.config().plugins)?;
     store.register(plugin);
@@ -1683,8 +1689,17 @@ tauri::Builder::default()
   ///   .plugin(plugin::init());
   /// ```
   #[must_use]
-  pub fn plugin<P: Plugin<R> + 'static>(mut self, plugin: P) -> Self {
-    self.plugins.register(Box::new(plugin));
+  pub fn plugin<P: Plugin<R> + 'static>(self, plugin: P) -> Self {
+    self.plugin_boxed(Box::new(plugin))
+  }
+
+  /// Adds a Tauri application plugin.
+  ///
+  /// This method is similar to [`Self::plugin`],
+  /// but accepts a boxed trait object instead of a generic type.
+  #[must_use]
+  pub fn plugin_boxed(mut self, plugin: Box<dyn Plugin<R>>) -> Self {
+    self.plugins.register(plugin);
     self
   }