fix(base-package): move equals to PackageInterfaceHandle for reference identity

PHP BasePackage::equals uses === (reference identity), unwrapping
AliasPackage on both sides first. A plain &self / &dyn PackageInterface
cannot express this, so implement it on the shared handle where the
Rc-based identity infrastructure (as_alias, get_alias_of, ptr_eq)
already lives, and drop the unimplementable trait stub.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

2 files changed, 14 insertions, 17 deletions

diff --git a/crates/shirabe/src/package/base_package.rs b/crates/shirabe/src/package/base_package.rs
index ec2fd3f..54abc13 100644
--- a/crates/shirabe/src/package/base_package.rs
+++ b/crates/shirabe/src/package/base_package.rs
@@ -84,32 +84,15 @@ pub trait BasePackage: PackageInterface + std::fmt::Display {
     fn set_repository_box(&mut self, repository: RepositoryInterfaceHandle);
     fn take_repository(&mut self) -> Option<RepositoryInterfaceHandle>;
 
-    // as_alias_package / as_complete_package_interface inherited from PackageInterface.
-
     fn as_alias_package_mut(&mut self) -> Option<&mut crate::package::AliasPackage> {
         None
     }
 
-    // get_name / get_pretty_name / get_names live on PackageInterface; the BasePackage
-    // duplicates were causing ambiguity at every call site (`pkg.get_name()` with
-    // pkg: &dyn BasePackage). Concrete impls already forward to name()/pretty_name().
-
-    // set_id, get_id, get_repository, get_unique_name, set_repository are inherited
-    // from PackageInterface; do not redeclare here to avoid trait-method ambiguity.
-
     fn is_platform(&self) -> bool {
         self.repository_opt()
             .map_or(false, |r| r.is::<PlatformRepository>())
     }
 
-    fn equals(&self, _package: &dyn PackageInterface) -> bool {
-        // TODO(phase-b): implement via reference identity (requires Rc/Arc)
-        // PHP uses === which is reference equality; unwraps AliasPackage on both sides
-        todo!("equals requires reference identity which needs Rc/Arc")
-    }
-
-    // get_pretty_string is inherited from PackageInterface.
-
     fn get_full_pretty_version(&self, truncate: bool, display_mode: DisplayMode) -> String {
         if display_mode == DisplayMode::SourceRefIfDev
             && (!self.is_dev()
diff --git a/crates/shirabe/src/package/handle.rs b/crates/shirabe/src/package/handle.rs
index 2e723b3..5df4fc0 100644
--- a/crates/shirabe/src/package/handle.rs
+++ b/crates/shirabe/src/package/handle.rs
@@ -1359,6 +1359,20 @@ macro_rules! impl_handle_downcasts {
 
 impl_handle_downcasts!(PackageInterfaceHandle);
 
+impl PackageInterfaceHandle {
+    pub fn equals(&self, package: &PackageInterfaceHandle) -> bool {
+        let self_real = match self.as_alias() {
+            Some(alias) => PackageInterfaceHandle::from(alias.get_alias_of()),
+            None => self.clone(),
+        };
+        let other_real = match package.as_alias() {
+            Some(alias) => PackageInterfaceHandle::from(alias.get_alias_of()),
+            None => package.clone(),
+        };
+        self_real.ptr_eq(&other_real)
+    }
+}
+
 impl PackageHandle {
     pub fn from_package(package: Package) -> Self {
         Self(Rc::new(RefCell::new(AnyPackage::Package(package))))