refactor(console): close HelperSet to a fixed set of four helpers

Replace the dynamic, string-keyed HelperSet (set/has/get/get_iterator,
HelperSetKey, deprecated set_command/get_command) with a closed set of
FormatterHelper, DebugFormatterHelper, ProcessHelper and QuestionHelper
instantiated by an argument-less constructor and exposed through typed
getters (get_formatter/get_debug_formatter/get_process/get_question).

The typed getters let ProcessHelper, QuestionHelper::write_error and
InitCommand::interact drop their downcast/placeholder todo!() stubs.
Dynamic registration of plugin-provided helpers is intentionally dropped
for now and tracked via TODO(plugin) comments.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/crates/shirabe-external-packages/src/symfony/console/command/command.rs b/crates/shirabe-external-packages/src/symfony/console/command/command.rs
index 2d94ad2..59aa915 100644
--- a/crates/shirabe-external-packages/src/symfony/console/command/command.rs
+++ b/crates/shirabe-external-packages/src/symfony/console/command/command.rs
@@ -822,9 +822,11 @@ impl Command for CommandData {
             Some(helper_set) => helper_set,
         };
 
-        // TODO(review): HelperSet::get() returns `Rc<RefCell<dyn HelperInterface>>`, but
-        // Command::getHelper() is typed `mixed` (PhpMixed) here and PhpMixed cannot hold a
-        // helper instance. The helper return modelling needs a dedicated type (Phase C).
+        // TODO(plugin): PHP's Command::getHelper($name) looks a helper up by string via
+        // HelperSet::get($name). The HelperSet is now a closed set exposing only typed getters
+        // (get_formatter/get_question/...), so a string-keyed lookup no longer exists. Callers
+        // should use the typed getters on the HelperSet directly; restoring name-based lookup is
+        // deferred until the plugin API (which is the only source of dynamically named helpers).
         let _ = helper_set;
         todo!()
     }