feat(symfony-console): implement the shell completion command plumbing

The _complete and completion commands were registered but always panicked:
get_class_of_command / instantiate_completion_output / tail_debug_log were
todo!() and the completion.bash resource was not shipped.

- make Command::complete return anyhow::Result so completion errors
  propagate to CompleteCommand's catch-all (exit code 2) like PHP
- add Command::get_class as the port hook for PHP's get_class() debug log;
  every command supplies its PHP FQCN via the delegation macro
- embed Resources/completion.bash at compile time (single-binary port);
  get_supported_shells becomes a static list
- implement tail_debug_log by moving the shared output handle into the
  'static process callback
- add OutputInterface::as_console_output so unsupported-shell errors go to
  stderr as in PHP
- fix CompletionInput::bind to keep the argument name PHP assigns in the
  foreach head even when the loop breaks on the first unset argument;
  application-level completion always hit this and returned no suggestions

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

1 files changed, 10 insertions, 2 deletions

diff --git a/crates/shirabe-external-packages/src/symfony/console/command/help_command.rs b/crates/shirabe-external-packages/src/symfony/console/command/help_command.rs
index 7c32a733..83ed4f5b 100644
--- a/crates/shirabe-external-packages/src/symfony/console/command/help_command.rs
+++ b/crates/shirabe-external-packages/src/symfony/console/command/help_command.rs
@@ -155,9 +155,17 @@ impl Command for HelpCommand {
         Ok(0)
     }
 
-    fn complete(&self, input: &CompletionInput, suggestions: &mut CompletionSuggestions) {
+    fn complete(
+        &self,
+        input: &CompletionInput,
+        suggestions: &mut CompletionSuggestions,
+    ) -> anyhow::Result<()> {
         self.complete_impl(input, suggestions);
+        Ok(())
     }
 
-    crate::delegate_command_trait_impls_to_inner!(inner);
+    crate::delegate_command_trait_impls_to_inner!(
+        inner,
+        "Symfony\\Component\\Console\\Command\\HelpCommand"
+    );
 }