refactor(composer): hold managers behind *Interface traits

Composer/PartialComposer exposed its RepositoryManager, InstallationManager,
EventDispatcher, Locker, DownloadManager, AutoloadGenerator and ArchiveManager
as concrete types, but Composer's public setters (setDownloadManager() etc.)
let plugins swap in subclasses. Introduce a *Interface trait per manager and
store each as Rc<RefCell<dyn ...Interface>> so a replacement is honored.

Only Composer's slots and the sinks fed from its accessors become trait
objects; managers injected concretely at construction keep their concrete
references, matching PHP semantics. Fluent setters on the affected classes now
return () and Locker::update_hash is de-generified to a boxed FnOnce so the
traits stay object-safe.

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

1 files changed, 2 insertions, 2 deletions

diff --git a/crates/shirabe/src/util/sync_helper.rs b/crates/shirabe/src/util/sync_helper.rs
index 6220f5c..8988795 100644
--- a/crates/shirabe/src/util/sync_helper.rs
+++ b/crates/shirabe/src/util/sync_helper.rs
@@ -1,6 +1,6 @@
 //! ref: composer/src/Composer/Util/SyncHelper.php
 
-use crate::downloader::DownloadManager;
+use crate::downloader::DownloadManagerInterface;
 use crate::downloader::DownloaderInterface;
 use crate::package::PackageInterfaceHandle;
 use crate::util::r#loop::Loop;
@@ -9,7 +9,7 @@ use shirabe_php_shim::PhpMixed;
 
 pub enum DownloaderOrManager<'a> {
     Interface(&'a std::rc::Rc<std::cell::RefCell<dyn DownloaderInterface>>),
-    Manager(&'a std::rc::Rc<std::cell::RefCell<DownloadManager>>),
+    Manager(&'a std::rc::Rc<std::cell::RefCell<dyn DownloadManagerInterface>>),
 }
 
 impl<'a> DownloaderOrManager<'a> {