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/command/diagnose_command.rs b/crates/shirabe/src/command/diagnose_command.rs
index 37009fb..68aec20 100644
--- a/crates/shirabe/src/command/diagnose_command.rs
+++ b/crates/shirabe/src/command/diagnose_command.rs
@@ -34,7 +34,7 @@ use crate::io::IOInterfaceImmutable;
 use crate::io::NullIO;
 use crate::json::JsonFile;
 use crate::json::JsonValidationException;
-use crate::package::Locker;
+use crate::package::LockerInterface;
 use crate::package::RootPackage;
 use crate::package::version::VersionParser;
 use crate::plugin::CommandEvent;
@@ -284,7 +284,7 @@ impl Command for DiagnoseCommand {
                 io.write_no_newline("Checking composer.lock: ");
                 let locker = c.get_locker().clone();
                 let locker = locker.borrow();
-                let r = self.check_composer_lock_schema(&locker)?;
+                let r = self.check_composer_lock_schema(&*locker)?;
                 self.output_result(r);
             }
         }
@@ -487,7 +487,7 @@ impl DiagnoseCommand {
         Ok(PhpMixed::Bool(true))
     }
 
-    fn check_composer_lock_schema(&self, locker: &Locker) -> anyhow::Result<PhpMixed> {
+    fn check_composer_lock_schema(&self, locker: &dyn LockerInterface) -> anyhow::Result<PhpMixed> {
         let json = locker.get_json_file();
 
         match json.validate_schema(JsonFile::LOCK_SCHEMA, None) {