feat(plugin): discover and list plugin-provided commands

Port Application::getPluginCommands: resolve the local composer with
plugins force-enabled, fall back to Factory::createGlobal, and collect
commands from CommandProvider capability adapters. PhpCommandProxy now
mirrors name/description/aliases/hidden over RPC so `list` output
matches upstream; input definitions remain TODO(plugin).

PhpClass::php_class_name returns an owned String because PHP-backed
proxies only know their class at runtime (the override-skip warning
prints get_class). CommandProvider::getCommands hands out shared
Rc<RefCell> handles since the commands are stored in the application.

Factory::createGlobal now propagates createConfig errors instead of
swallowing them, and Application::getComposer only catches the
exception classes upstream catches, so a ParsingException reaches
doRun's GithubActionError path as in Composer.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/crates/shirabe/src/factory.rs b/crates/shirabe/src/factory.rs
index 9a84117e..fe3b5289 100644
--- a/crates/shirabe/src/factory.rs
+++ b/crates/shirabe/src/factory.rs
@@ -903,11 +903,11 @@ impl Factory {
         io: std::rc::Rc<std::cell::RefCell<dyn IOInterface>>,
         disable_plugins: DisablePlugins,
         disable_scripts: bool,
-    ) -> Option<PartialComposerHandle> {
+    ) -> anyhow::Result<Option<PartialComposerHandle>> {
         let factory = Self::default();
 
-        let config = Self::create_config(Some(io.clone()), None).ok()?;
-        factory.create_global_composer(io, &config, disable_plugins, disable_scripts, true)
+        let config = Self::create_config(Some(io.clone()), None)?;
+        Ok(factory.create_global_composer(io, &config, disable_plugins, disable_scripts, true))
     }
 
     fn add_local_repository(