feat(event-dispatcher): unify event dispatch via EventInterface trait

Extract a superclass-trait EventInterface from the base Event.

pool_builder's PrePoolCreateEvent stays deferred: its constructor needs
owned, non-cloneable Request and repository boxes the builder only holds
by reference (owned-payload blocker). The event is plugin-only, so its
construction is re-tagged TODO(plugin).

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

4 files changed, 15 insertions, 17 deletions

diff --git a/crates/shirabe/src/command/base_command.rs b/crates/shirabe/src/command/base_command.rs
index d7418ff..c98bc2b 100644
--- a/crates/shirabe/src/command/base_command.rs
+++ b/crates/shirabe/src/command/base_command.rs
@@ -378,15 +378,17 @@ impl<C: HasBaseCommandData> BaseCommand for C {
         if let Some(composer) = composer.as_ref() {
             // TODO(phase-b): requires inner Symfony Command get_name access
             let command_name: String = todo!();
-            let pre_command_run_event = PreCommandRunEvent::new(
+            let mut pre_command_run_event = PreCommandRunEvent::new(
                 PluginEvents::PRE_COMMAND_RUN.to_string(),
                 input,
                 command_name,
             );
-            // TODO(phase-b): event_dispatcher.dispatch expects Option<Event>; need wrapper from
-            // PreCommandRunEvent.
-            let _ = composer.borrow_partial().get_event_dispatcher();
-            let _ = pre_command_run_event.get_name();
+            let pre_command_run_event_name = pre_command_run_event.get_name().to_string();
+            let dispatcher = composer.borrow_partial().get_event_dispatcher();
+            dispatcher.borrow_mut().dispatch(
+                Some(&pre_command_run_event_name),
+                Some(&mut pre_command_run_event),
+            )?;
         }
 
         if input.borrow().has_parameter_option(&["--no-ansi"], false)
diff --git a/crates/shirabe/src/command/remove_command.rs b/crates/shirabe/src/command/remove_command.rs
index ddb14f0..1857b17 100644
--- a/crates/shirabe/src/command/remove_command.rs
+++ b/crates/shirabe/src/command/remove_command.rs
@@ -485,18 +485,17 @@ impl RemoveCommand {
             root_package.set_dev_requires(links.remove("require-dev").unwrap_or_default());
         }
 
-        // TODO(plugin): dispatch CommandEvent(PluginEvents::COMMAND, 'remove', input, output)
-        let command_event = crate::plugin::CommandEvent::new(
+        let mut command_event = crate::plugin::CommandEvent::new(
             crate::plugin::PluginEvents::COMMAND,
             "remove",
             input.clone(),
             output,
         );
+        let command_event_name = command_event.get_name().to_string();
         composer
             .get_event_dispatcher()
             .borrow_mut()
-            // TODO(phase-b): dispatch expects Option<Event>; CommandEvent is a different type
-            .dispatch(Some(command_event.get_name()), None);
+            .dispatch(Some(&command_event_name), Some(&mut command_event));
 
         let allow_plugins = composer.get_config().borrow_mut().get("allow-plugins");
         let removed_plugins: Vec<String> =
diff --git a/crates/shirabe/src/command/show_command.rs b/crates/shirabe/src/command/show_command.rs
index 7ee103a..1ce91cb 100644
--- a/crates/shirabe/src/command/show_command.rs
+++ b/crates/shirabe/src/command/show_command.rs
@@ -452,7 +452,7 @@ impl ShowCommand {
 
         if let Some(ref composer) = composer {
             let composer = crate::command::composer_full(composer);
-            let command_event = CommandEvent::new6(
+            let mut command_event = CommandEvent::new6(
                 PluginEvents::COMMAND,
                 "show",
                 input.clone(),
@@ -460,13 +460,11 @@ impl ShowCommand {
                 vec![],
                 IndexMap::new(),
             );
-            // TODO(phase-b): EventDispatcher::dispatch wants Option<Event>, but PHP passes
-            // the CommandEvent subclass directly. Phase D will introduce trait-based dispatch.
-            let _event_name = command_event.get_name().to_string();
+            let command_event_name = command_event.get_name().to_string();
             composer
                 .get_event_dispatcher()
                 .borrow_mut()
-                .dispatch(Some(&_event_name), None)?;
+                .dispatch(Some(&command_event_name), Some(&mut command_event))?;
         }
 
         if input.borrow().get_option("latest").as_bool() == Some(true) && composer.is_none() {
diff --git a/crates/shirabe/src/command/update_command.rs b/crates/shirabe/src/command/update_command.rs
index a4fbf99..751203c 100644
--- a/crates/shirabe/src/command/update_command.rs
+++ b/crates/shirabe/src/command/update_command.rs
@@ -306,12 +306,11 @@ impl UpdateCommand {
 
         let mut command_event =
             CommandEvent::new(PluginEvents::COMMAND, "update", input.clone(), output);
-        // TODO(phase-b): dispatch should accept the CommandEvent itself; passing the
-        // event by name only for now to keep types aligned with EventDispatcher::dispatch.
+        let command_event_name = command_event.get_name().to_string();
         composer
             .get_event_dispatcher()
             .borrow_mut()
-            .dispatch(Some(command_event.get_name()), None)?;
+            .dispatch(Some(&command_event_name), Some(&mut command_event))?;
 
         composer
             .get_installation_manager()