fix(repository-manager): fail explicitly on an unknown repository class

createRepository instantiates `new $class(...)` from the name registered
for the type. The port dispatches over the classes it implements, and the
remaining arm was a todo!(). setRepositoryClass is public API, so a plugin
registering a class of its own reached it and panicked.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

1 files changed, 7 insertions, 5 deletions

diff --git a/crates/shirabe/src/repository/repository_manager.rs b/crates/shirabe/src/repository/repository_manager.rs
index 5f74fc90..7fd2f80a 100644
--- a/crates/shirabe/src/repository/repository_manager.rs
+++ b/crates/shirabe/src/repository/repository_manager.rs
@@ -10,7 +10,7 @@ use crate::repository::RepositoryInterfaceHandle;
 use crate::util::HttpDownloader;
 use crate::util::ProcessExecutor;
 use indexmap::IndexMap;
-use shirabe_php_shim::{InvalidArgumentException, PhpMixed, json_encode};
+use shirabe_php_shim::{InvalidArgumentException, PhpMixed, RuntimeException, json_encode};
 use shirabe_semver::constraint::AnyConstraint;
 
 #[derive(Debug)]
@@ -191,10 +191,12 @@ impl RepositoryManager {
                     Some(self.process.clone()),
                 )?,
             )),
-            other => todo!(
-                "dynamic class instantiation is not implemented for repository class {}",
-                other
-            ),
+            // TODO(plugin): `setRepositoryClass` lets a plugin register a repository class of
+            // its own, which needs a Rust-side counterpart before it can be built here.
+            other => Err(anyhow::anyhow!(RuntimeException {
+                message: format!("Repository class has no Rust implementation: {other}"),
+                code: 0,
+            })),
         }
     }