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, 18 insertions, 28 deletions

diff --git a/crates/shirabe/src/command/show_command.rs b/crates/shirabe/src/command/show_command.rs
index aa63d8e7..6c693e62 100644
--- a/crates/shirabe/src/command/show_command.rs
+++ b/crates/shirabe/src/command/show_command.rs
@@ -359,14 +359,11 @@ impl ShowCommand {
         if let Some(ref mp) = matched_package
             && mp.as_complete().is_none()
         {
-            return Err(LogicException {
-                    message: format!(
-                        "ShowCommand::getPackage can only work with CompletePackageInterface, but got {}",
-                        shirabe_php_shim::get_class(&PhpMixed::Null)
-                    ),
-                    code: 0,
-                }
-                .into());
+            return Err(LogicException::new(format!(
+                "ShowCommand::getPackage can only work with CompletePackageInterface, but got {}",
+                shirabe_php_shim::get_class(&PhpMixed::Null)
+            ))
+            .into());
         }
 
         let matched_package = matched_package.and_then(|mp| mp.as_complete());
@@ -1817,10 +1814,9 @@ impl Command for ShowCommand {
                 .as_string()
                 .is_some()
             {
-                return Err(InvalidArgumentException {
-                    message: "You cannot use --self together with a package name".to_string(),
-                    code: 0,
-                }
+                return Err(InvalidArgumentException::new(
+                    "You cannot use --self together with a package name".to_string(),
+                )
                 .into());
             }
             installed_repo = RepositoryInterfaceHandle::new(InstalledRepository::new(vec![
@@ -1931,10 +1927,7 @@ impl Command for ShowCommand {
                     .borrow_mut()
                     .is_locked()
             {
-                return Err(UnexpectedValueException {
-                    message: "A valid composer.json and composer.lock files is required to run this command with --locked".to_string(),
-                    code: 0,
-                }
+                return Err(UnexpectedValueException::new("A valid composer.json and composer.lock files is required to run this command with --locked".to_string())
                 .into());
             }
             let composer_ref = crate::composer::composer_full(composer.as_ref().unwrap());
@@ -2090,14 +2083,11 @@ impl Command for ShowCommand {
                         .collect::<Vec<_>>(),
                 )
             {
-                return Err(InvalidArgumentException {
-                                message: format!(
-                                    "Package \"{}\" is installed but not a direct dependent of the root package.",
-                                    pkg.get_name()
-                                ),
-                                code: 0,
-                            }
-                            .into());
+                return Err(InvalidArgumentException::new(format!(
+                    "Package \"{}\" is installed but not a direct dependent of the root package.",
+                    pkg.get_name()
+                ))
+                .into());
             }
 
             if matched_package.is_none() {
@@ -2123,10 +2113,10 @@ impl Command for ShowCommand {
                     hint.push_str(", try using --available (-a) to show all available packages");
                 }
 
-                return Err(InvalidArgumentException {
-                    message: format!("Package \"{}\" not found{}.", pf, hint),
-                    code: 0,
-                }
+                return Err(InvalidArgumentException::new(format!(
+                    "Package \"{}\" not found{}.",
+                    pf, hint
+                ))
                 .into());
             }
             single_package = matched_package;