refactor(xdebug-handler): extract composer/xdebug_handler into the shirabe-xdebug-handler crate

Move `Composer\XdebugHandler` out of shirabe-external-packages and into
its own crate, so the path is `shirabe_xdebug_handler::XdebugHandler`
instead of
`shirabe_external_packages::composer::xdebug_handler::XdebugHandler`.

Standing alone, the stub no longer sits in a crate that shirabe-php-rpc
depends on, so drop the dependency-cycle rationale from the comments that
explain why callers reach for shirabe_php_rpc directly.

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

1 files changed, 2 insertions, 2 deletions

diff --git a/crates/shirabe/src/command/diagnose_command.rs b/crates/shirabe/src/command/diagnose_command.rs
index eade37fc..2af2acfc 100644
--- a/crates/shirabe/src/command/diagnose_command.rs
+++ b/crates/shirabe/src/command/diagnose_command.rs
@@ -888,8 +888,8 @@ impl DiagnoseCommand {
             warnings.insert("xdebug_profile".to_string(), PhpMixed::Bool(true));
         } else if diagnostics.xdebug_active {
             // PHP: XdebugHandler::isXdebugActive(). As with IniHelper::get_all, the port of that
-            // method in shirabe_external_packages cannot reach the PHP RPC bridge (the dependency
-            // would cycle), so the real runtime is queried through the diagnose payload instead.
+            // method in shirabe_xdebug_handler is a stub, so the real runtime is queried through
+            // the diagnose payload instead.
             warnings.insert("xdebug_loaded".to_string(), PhpMixed::Bool(true));
         }