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>

3 files changed, 16 insertions, 26 deletions

diff --git a/crates/shirabe/src/io/base_io.rs b/crates/shirabe/src/io/base_io.rs
index 5dd7682f..52ef9a82 100644
--- a/crates/shirabe/src/io/base_io.rs
+++ b/crates/shirabe/src/io/base_io.rs
@@ -145,13 +145,11 @@ pub trait BaseIO: IOInterface {
                 }
 
                 if !Preg::is_match(php_regex!(r"{^[.A-Za-z0-9_]+$}"), &token_str) {
-                    return Err(anyhow::anyhow!(UnexpectedValueException {
-                        message: format!(
-                            "Your github oauth token for {} contains invalid characters: \"{}\"",
-                            domain, token_str
-                        ),
-                        code: 0,
-                    }));
+                    return Err(UnexpectedValueException::new(format!(
+                        "Your github oauth token for {} contains invalid characters: \"{}\"",
+                        domain, token_str
+                    ))
+                    .into());
                 }
                 self.check_and_set_authentication(
                     domain,
diff --git a/crates/shirabe/src/io/buffer_io.rs b/crates/shirabe/src/io/buffer_io.rs
index bbe1db9f..d1224fdc 100644
--- a/crates/shirabe/src/io/buffer_io.rs
+++ b/crates/shirabe/src/io/buffer_io.rs
@@ -30,10 +30,9 @@ impl BufferIO {
         let stream = match fopen("php://memory", "rw") {
             Ok(stream) => stream,
             Err(_) => {
-                return Err(RuntimeException {
-                    message: "Unable to open memory output stream".to_string(),
-                    code: 0,
-                }
+                return Err(RuntimeException::new(
+                    "Unable to open memory output stream".to_string(),
+                )
                 .into());
             }
         };
@@ -116,10 +115,7 @@ impl BufferIO {
 
         let mut input = self.inner.input.borrow_mut();
         let Some(streamable) = input.as_streamable_mut() else {
-            return Err(RuntimeException {
-                message: "Setting the user inputs requires at least the version 3.2 of the symfony/console component.".to_string(),
-                code: 0,
-            }
+            return Err(RuntimeException::new("Setting the user inputs requires at least the version 3.2 of the symfony/console component.".to_string())
             .into());
         };
 
@@ -133,10 +129,9 @@ impl BufferIO {
         let stream = match fopen("php://memory", "r+") {
             Ok(stream) => stream,
             Err(_) => {
-                return Err(RuntimeException {
-                    message: "Unable to open memory output stream".to_string(),
-                    code: 0,
-                }
+                return Err(RuntimeException::new(
+                    "Unable to open memory output stream".to_string(),
+                )
                 .into());
             }
         };
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)
     }