test: port Composer tests unblocked by mockall, add seams

Port 11 categories of previously-ignored Composer tests now reachable with
the mockall crate: DownloadManager, VCS/Perforce/File downloaders,
VersionSelector, PlatformRepository, Auditor, installer/FilesystemRepository,
RootPackageLoader, util auth/http, commands, and Cache.

Extract test seams additively on concrete structs as *Interface traits
(Runtime, HhvmDetector, VersionGuesser, RepositorySet, Perforce,
BinaryInstaller) plus mock-field seams (Cache, Filesystem); consumers take
trait objects. Mocks are defined locally in the test crates via
mockall::mock!, since automock-generated mocks are cfg(test)-gated and
invisible across the integration-test boundary.

dataProviders are ported in full; tests blocked by unported shims stay
#[ignore] with documented reasons rather than reduced or weakened.

Fix product bugs surfaced by the ports:
- util/github: use the exception code, not the HTTP status, for 401/403
- advisory: serialize empty audit maps as [] to match PHP json_encode
- repository/filesystem and downloader/file: fix RefCell double-borrow panics

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

1 files changed, 5 insertions, 4 deletions

diff --git a/crates/shirabe/src/package/loader/root_package_loader.rs b/crates/shirabe/src/package/loader/root_package_loader.rs
index 556f36e..c0101ac 100644
--- a/crates/shirabe/src/package/loader/root_package_loader.rs
+++ b/crates/shirabe/src/package/loader/root_package_loader.rs
@@ -11,6 +11,7 @@ use crate::package::loader::ArrayLoader;
 use crate::package::loader::LoaderInterface;
 use crate::package::loader::ValidatingArrayLoader;
 use crate::package::version::VersionGuesser;
+use crate::package::version::VersionGuesserInterface;
 use crate::package::version::VersionParser;
 use crate::package::{RootPackage, STABILITIES, SUPPORTED_LINK_TYPES};
 use crate::repository::RepositoryFactory;
@@ -23,7 +24,7 @@ pub struct RootPackageLoader {
     inner: ArrayLoader,
     manager: std::rc::Rc<std::cell::RefCell<RepositoryManager>>,
     config: std::rc::Rc<std::cell::RefCell<Config>>,
-    version_guesser: VersionGuesser,
+    version_guesser: Box<dyn VersionGuesserInterface>,
     io: Option<std::rc::Rc<std::cell::RefCell<dyn IOInterface>>>,
 }
 
@@ -32,19 +33,19 @@ impl RootPackageLoader {
         manager: std::rc::Rc<std::cell::RefCell<RepositoryManager>>,
         config: std::rc::Rc<std::cell::RefCell<Config>>,
         parser: Option<VersionParser>,
-        version_guesser: Option<VersionGuesser>,
+        version_guesser: Option<Box<dyn VersionGuesserInterface>>,
         io: Option<std::rc::Rc<std::cell::RefCell<dyn IOInterface>>>,
     ) -> Self {
         let inner = ArrayLoader::new(parser, true);
         let version_guesser = version_guesser.unwrap_or_else(|| {
             let mut process_executor = ProcessExecutor::new(io.clone());
             process_executor.enable_async();
-            VersionGuesser::new(
+            Box::new(VersionGuesser::new(
                 config.clone(),
                 std::rc::Rc::new(std::cell::RefCell::new(process_executor)),
                 inner.version_parser.clone(),
                 io.clone(),
-            )
+            ))
         });
         Self {
             inner,