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, 3 insertions, 3 deletions

diff --git a/crates/shirabe/src/installer/project_installer.rs b/crates/shirabe/src/installer/project_installer.rs
index 351fd35..83ffbb2 100644
--- a/crates/shirabe/src/installer/project_installer.rs
+++ b/crates/shirabe/src/installer/project_installer.rs
@@ -1,6 +1,6 @@
 //! ref: composer/src/Composer/Installer/ProjectInstaller.php
 
-use crate::downloader::DownloadManager;
+use crate::downloader::DownloadManagerInterface;
 use crate::installer::InstallerInterface;
 use crate::package::PackageInterfaceHandle;
 use crate::repository::InstalledRepositoryInterface;
@@ -10,14 +10,14 @@ use shirabe_php_shim::{InvalidArgumentException, PhpMixed};
 #[derive(Debug)]
 pub struct ProjectInstaller {
     install_path: String,
-    download_manager: std::rc::Rc<std::cell::RefCell<DownloadManager>>,
+    download_manager: std::rc::Rc<std::cell::RefCell<dyn DownloadManagerInterface>>,
     filesystem: std::rc::Rc<std::cell::RefCell<Filesystem>>,
 }
 
 impl ProjectInstaller {
     pub fn new(
         install_path: &str,
-        dm: std::rc::Rc<std::cell::RefCell<DownloadManager>>,
+        dm: std::rc::Rc<std::cell::RefCell<dyn DownloadManagerInterface>>,
         fs: std::rc::Rc<std::cell::RefCell<Filesystem>>,
     ) -> Self {
         let install_path = format!("{}/", install_path.replace('\\', "/").trim_end_matches('/'));