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>

1 files changed, 1 insertions, 1 deletions

diff --git a/crates/shirabe-external-packages/src/symfony/filesystem/filesystem.rs b/crates/shirabe-external-packages/src/symfony/filesystem/filesystem.rs
index b1245a61..8834f724 100644
--- a/crates/shirabe-external-packages/src/symfony/filesystem/filesystem.rs
+++ b/crates/shirabe-external-packages/src/symfony/filesystem/filesystem.rs
@@ -420,7 +420,7 @@ impl Filesystem {
             shirabe_php_shim::SKIP_DOTS
         };
         let dir = shirabe_php_shim::recursive_directory_iterator(&origin_dir, flags)
-            .map_err(|e| anyhow::anyhow!("{}", e.message))?;
+            .map_err(|e| anyhow::anyhow!("{}", e.get_message()))?;
         let iterator = shirabe_php_shim::recursive_iterator_iterator(
             dir,
             shirabe_php_shim::RecursiveIteratorIterator::SELF_FIRST,