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, 4 insertions, 7 deletions

diff --git a/crates/shirabe/src/io/console_io.rs b/crates/shirabe/src/io/console_io.rs
index 12b70318..443a3e51 100644
--- a/crates/shirabe/src/io/console_io.rs
+++ b/crates/shirabe/src/io/console_io.rs
@@ -348,7 +348,7 @@ impl ConsoleIO {
         let mut input = self.input.borrow_mut();
         question_helper
             .ask(&mut *input, error_output, question)?
-            .map_err(anyhow::Error::new)
+            .map_err(anyhow::Error::from)
     }
 }
 
@@ -490,18 +490,15 @@ impl IOInterfaceImmutable for ConsoleIO {
             >,
         > = Box::new(move |answer: Option<PhpMixed>| {
             validator(answer.unwrap_or(PhpMixed::Null)).map_err(|e| {
-                shirabe_external_packages::symfony::console::exception::InvalidArgumentException(
-                    shirabe_php_shim::InvalidArgumentException {
-                        message: e.to_string(),
-                        code: 0,
-                    },
+                shirabe_external_packages::symfony::console::exception::InvalidArgumentException::new(
+                    e.to_string(),
                 )
             })
         });
         question.set_validator(Some(adapted));
         question
             .set_max_attempts(attempts)
-            .map_err(|e| anyhow::anyhow!(e.0.message))?;
+            .map_err(|e| anyhow::anyhow!(e.0.get_message().to_string()))?;
 
         self.ask_question(&question)
     }