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, 17 insertions, 22 deletions

diff --git a/crates/shirabe/src/repository/vcs/svn_driver.rs b/crates/shirabe/src/repository/vcs/svn_driver.rs
index 716b1943..84e3a20d 100644
--- a/crates/shirabe/src/repository/vcs/svn_driver.rs
+++ b/crates/shirabe/src/repository/vcs/svn_driver.rs
@@ -14,6 +14,7 @@ use crate::util::Url;
 use chrono::{DateTime, FixedOffset, Utc};
 use indexmap::IndexMap;
 use shirabe_external_packages::composer::pcre::{CaptureKey, Preg};
+use shirabe_php_shim::Catch as _;
 use shirabe_php_shim::{
     PhpMixed, RuntimeException, php_regex, stripos, strrpos, strtr, substr, trim,
 };
@@ -199,14 +200,14 @@ impl SvnDriver {
                 Ok(c) => c,
                 Err(e) => {
                     // PHP catches only TransportException; other exceptions propagate uncaught.
-                    if e.downcast_ref::<TransportException>().is_none() {
+                    if !e.is_instanceof::<TransportException>() {
                         return Err(e);
                     }
                     let message = e
-                        .downcast_ref::<TransportException>()
+                        .catch::<TransportException>()
                         .unwrap()
-                        .message
-                        .clone();
+                        .get_message()
+                        .to_string();
                     if stripos(&message, "path not found").is_none()
                         && stripos(&message, "svn: warning: W160013").is_none()
                     {
@@ -277,8 +278,8 @@ impl SvnDriver {
         ) {
             Ok(o) => o,
             Err(e) => {
-                if let Some(e) = e.downcast_ref::<RuntimeException>() {
-                    return Err(TransportException::new(e.message.clone(), 0).into());
+                if let Some(e) = e.catch::<RuntimeException>() {
+                    return Err(TransportException::new(e.get_message().to_string(), 0).into());
                 }
                 return Err(e);
             }
@@ -567,24 +568,18 @@ impl SvnDriver {
             Ok(o) => Ok(o),
             Err(e) => {
                 if self.util.as_mut().unwrap().binary_version().is_none() {
-                    return Err(RuntimeException {
-                        message: format!(
-                            "Failed to load {}, svn was not found, check that it is installed and in your PATH env.\n\n{}",
-                            self.inner.url,
-                            self.inner.process.borrow().get_error_output(),
-                        ),
-                        code: 0,
-                    }
+                    return Err(RuntimeException::new(format!(
+                        "Failed to load {}, svn was not found, check that it is installed and in your PATH env.\n\n{}",
+                        self.inner.url,
+                        self.inner.process.borrow().get_error_output(),
+                    ))
                     .into());
                 }
 
-                Err(RuntimeException {
-                    message: format!(
-                        "Repository {} could not be processed, {}",
-                        self.inner.url, e,
-                    ),
-                    code: 0,
-                }
+                Err(RuntimeException::new(format!(
+                    "Repository {} could not be processed, {}",
+                    self.inner.url, e,
+                ))
                 .into())
             }
         }
@@ -655,7 +650,7 @@ impl crate::repository::vcs::VcsDriverInterface for SvnDriver {
         match self.get_composer_information(identifier) {
             Ok(info) => Ok(info.is_some()),
             Err(e) => {
-                if e.downcast_ref::<TransportException>().is_some() {
+                if e.is_instanceof::<TransportException>() {
                     Ok(false)
                 } else {
                     Err(e)