feat(php-shim): give ported exceptions PHP's class hierarchy

Ported exceptions were flat structs reached with `downcast_ref`, so
Composer's `catch (\RuntimeException $e)` only matched the exact leaf
type and `get_class($e)` had nothing to report. Each exception now
embeds an instance of the class it extends and travels inside an
`AnyThrowable`; `Catch::catch`/`catch_mut` walk that chain, and
`PhpClass::php_class_name` yields the PHP FQCN.

Dropping the `std::error::Error` impls from the exception types leaves
`AnyThrowable` as the only route into an `anyhow::Error`, so the walk
cannot be bypassed. A `no_exception_downcast` linter catches the
`downcast::<X>()` calls that would now silently answer `None`.

Three sites change behavior as a result: the `TransportException`
exit-code override reaches `MaxFileSizeExceededException`, the
`catch (\LogicException)` in findSimilar() reaches its subclasses, and
rendered exception titles carry the real class name rather than a
guess. `get_class_err()` is no longer a `todo!()`, which re-enables
FilesystemRepositoryTest::testCorruptedRepositoryFile.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

4 files changed, 13 insertions, 9 deletions

diff --git a/crates/shirabe/tests/repository/vcs/git_bitbucket_driver_test.rs b/crates/shirabe/tests/repository/vcs/git_bitbucket_driver_test.rs
index 4d84bcf2..67e9c8a9 100644
--- a/crates/shirabe/tests/repository/vcs/git_bitbucket_driver_test.rs
+++ b/crates/shirabe/tests/repository/vcs/git_bitbucket_driver_test.rs
@@ -10,6 +10,7 @@ use shirabe::repository::vcs::GitBitbucketDriver;
 use shirabe::util::filesystem::Filesystem;
 use shirabe::util::http_downloader::{HttpDownloader, HttpDownloaderMockHandler};
 use shirabe::util::process_executor::ProcessExecutor;
+use shirabe_php_shim::Catch as _;
 use shirabe_php_shim::{InvalidArgumentException, PhpMixed, RuntimeException};
 use tempfile::TempDir;
 
@@ -112,11 +113,11 @@ fn test_get_root_identifier_wrong_scm_type() {
 
     let err = driver.get_root_identifier().unwrap_err();
     let runtime = err
-        .downcast_ref::<RuntimeException>()
+        .catch::<RuntimeException>()
         .expect("expected RuntimeException");
     assert_eq!(
         "https://bitbucket.org/user/repo.git does not appear to be a git repository, use https://bitbucket.org/user/repo but remember that Bitbucket no longer supports the mercurial repositories. https://bitbucket.org/blog/sunsetting-mercurial-support-in-bitbucket",
-        runtime.message
+        runtime.get_message()
     );
 }
 
@@ -250,7 +251,7 @@ fn test_initialize_invalid_repository_url() {
     let result = get_driver("https://bitbucket.org/acme", io, config, http_downloader);
     let err = result.unwrap_err();
     assert!(
-        err.downcast_ref::<InvalidArgumentException>().is_some(),
+        err.is_instanceof::<InvalidArgumentException>(),
         "expected InvalidArgumentException, got: {err:?}"
     );
 }
diff --git a/crates/shirabe/tests/repository/vcs/git_driver_test.rs b/crates/shirabe/tests/repository/vcs/git_driver_test.rs
index 7a85d4cc..8494c1ca 100644
--- a/crates/shirabe/tests/repository/vcs/git_driver_test.rs
+++ b/crates/shirabe/tests/repository/vcs/git_driver_test.rs
@@ -12,6 +12,7 @@ use shirabe::util::filesystem::Filesystem;
 use shirabe::util::http_downloader::HttpDownloaderMockHandler;
 use shirabe::util::platform::Platform;
 use shirabe::util::process_executor::MockHandler;
+use shirabe_php_shim::Catch as _;
 use shirabe_php_shim::{PhpMixed, RuntimeException};
 use tempfile::TempDir;
 
@@ -293,7 +294,7 @@ fn test_file_get_content_invalid_identifier() {
     assert_eq!(None, driver.get_file_content("file.txt", "h").unwrap());
 
     let err = driver.get_file_content("file.txt", "-h").unwrap_err();
-    assert!(err.downcast_ref::<RuntimeException>().is_some());
+    assert!(err.is_instanceof::<RuntimeException>());
 }
 
 #[test]
@@ -324,5 +325,5 @@ fn test_get_change_date_invalid_identifier() {
     let mut driver = GitDriver::new(repo_config, io, config, http_downloader, process);
 
     let err = driver.get_change_date("-n1 --format=%at HEAD").unwrap_err();
-    assert!(err.downcast_ref::<RuntimeException>().is_some());
+    assert!(err.is_instanceof::<RuntimeException>());
 }
diff --git a/crates/shirabe/tests/repository/vcs/hg_driver_test.rs b/crates/shirabe/tests/repository/vcs/hg_driver_test.rs
index be36f412..4245e140 100644
--- a/crates/shirabe/tests/repository/vcs/hg_driver_test.rs
+++ b/crates/shirabe/tests/repository/vcs/hg_driver_test.rs
@@ -11,6 +11,7 @@ use shirabe::repository::vcs::HgDriver;
 use shirabe::util::filesystem::Filesystem;
 use shirabe::util::http_downloader::HttpDownloaderMockHandler;
 use shirabe::util::process_executor::MockHandler;
+use shirabe_php_shim::Catch as _;
 use shirabe_php_shim::{PhpMixed, RuntimeException};
 use tempfile::TempDir;
 
@@ -141,7 +142,7 @@ fn test_file_get_content_invalid_identifier() {
     assert_eq!(None, driver.get_file_content("file.txt", "h").unwrap());
 
     let err = driver.get_file_content("file.txt", "-h").unwrap_err();
-    assert!(err.downcast_ref::<RuntimeException>().is_some());
+    assert!(err.is_instanceof::<RuntimeException>());
 }
 
 #[test]
@@ -168,5 +169,5 @@ fn test_get_change_date_invalid_identifier() {
     let driver = HgDriver::new(repo_config, io, config, http_downloader, process);
 
     let err = driver.get_change_date("-r foo").unwrap_err();
-    assert!(err.downcast_ref::<RuntimeException>().is_some());
+    assert!(err.is_instanceof::<RuntimeException>());
 }
diff --git a/crates/shirabe/tests/repository/vcs/svn_driver_test.rs b/crates/shirabe/tests/repository/vcs/svn_driver_test.rs
index 6a74063d..bc45b082 100644
--- a/crates/shirabe/tests/repository/vcs/svn_driver_test.rs
+++ b/crates/shirabe/tests/repository/vcs/svn_driver_test.rs
@@ -11,6 +11,7 @@ use shirabe::repository::vcs::SvnDriver;
 use shirabe::util::filesystem::Filesystem;
 use shirabe::util::http_downloader::HttpDownloaderMockHandler;
 use shirabe::util::process_executor::MockHandler;
+use shirabe_php_shim::Catch as _;
 use shirabe_php_shim::{PhpMixed, RuntimeException};
 use tempfile::TempDir;
 
@@ -130,10 +131,10 @@ fn test_wrong_credentials_in_url() {
     let mut svn = SvnDriver::new(repo_config, console, config, http_downloader, process);
     let err = svn.initialize().unwrap_err();
     let runtime = err
-        .downcast_ref::<RuntimeException>()
+        .catch::<RuntimeException>()
         .expect("expected RuntimeException");
     assert_eq!(
         "Repository https://till:secret@corp.svn.local/repo could not be processed, wrong credentials provided (svn: OPTIONS of 'https://corp.svn.local/repo': authorization failed: Could not authenticate to server: rejected Basic challenge (https://corp.svn.local/))",
-        runtime.message
+        runtime.get_message()
     );
 }