refactor(plugin): return borrowed plugins from get_plugins, drop clone_box

PluginManager::get_plugins cloned each plugin through a Rust-only
`clone_box` stub (`todo!()`). PHP's getPlugins() returns `$this->plugins`
directly and the objects are shared by reference, so borrow the stored
instances (`&[Box<dyn PluginInterface>]`) instead of cloning. The sole
caller is adjusted and `PluginInterface::clone_box` is removed.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

2 files changed, 6 insertions, 7 deletions

diff --git a/crates/shirabe/src/plugin/plugin_interface.rs b/crates/shirabe/src/plugin/plugin_interface.rs
index d335bf0..486dbea 100644
--- a/crates/shirabe/src/plugin/plugin_interface.rs
+++ b/crates/shirabe/src/plugin/plugin_interface.rs
@@ -15,10 +15,6 @@ pub trait PluginInterface: std::fmt::Debug {
 
     fn uninstall(&mut self, composer: &ComposerHandle, io: Rc<RefCell<dyn IOInterface>>);
 
-    fn clone_box(&self) -> Box<dyn PluginInterface> {
-        todo!()
-    }
-
     // TODO(plugin): PHP-side `instanceof` checks for EventSubscriberInterface / Capable.
     // EventSubscriberInterface is not dyn-compatible (its only method is associated, not
     // a `&self` method), so we expose a boolean predicate instead.
diff --git a/crates/shirabe/src/plugin/plugin_manager.rs b/crates/shirabe/src/plugin/plugin_manager.rs
index e8377f3..da64cee 100644
--- a/crates/shirabe/src/plugin/plugin_manager.rs
+++ b/crates/shirabe/src/plugin/plugin_manager.rs
@@ -182,8 +182,11 @@ impl PluginManager {
     }
 
     /// Gets all currently active plugin instances
-    pub fn get_plugins(&self) -> Vec<Box<dyn PluginInterface>> {
-        self.plugins.iter().map(|p| p.clone_box()).collect()
+    ///
+    /// PHP returns `$this->plugins` directly; the plugin objects are shared by reference, so this
+    /// borrows the stored instances rather than cloning them.
+    pub fn get_plugins(&self) -> &[Box<dyn PluginInterface>] {
+        &self.plugins
     }
 
     /// Gets all currently active plugin instances
@@ -723,7 +726,7 @@ impl PluginManager {
     ) -> Vec<Box<dyn Capability>> {
         // TODO(plugin): aggregate capabilities across all loaded plugins
         let mut capabilities: Vec<Box<dyn Capability>> = vec![];
-        for plugin in &self.get_plugins() {
+        for plugin in self.get_plugins() {
             if let Ok(Some(capability)) =
                 self.get_plugin_capability(&**plugin, capability_class_name, ctor_args.clone())
             {