refactor(seld-signal): extract seld/signal into the shirabe-seld-signal crate

Move `Seld\Signal` out of shirabe-external-packages and into its own
crate, so the path is `shirabe_seld_signal::SignalHandler` instead of
`shirabe_external_packages::seld::signal::SignalHandler`.

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

1 files changed, 0 insertions, 25 deletions

diff --git a/crates/shirabe-external-packages/src/seld/signal/signal_handler.rs b/crates/shirabe-external-packages/src/seld/signal/signal_handler.rs
deleted file mode 100644
index b2f1873e..00000000
--- a/crates/shirabe-external-packages/src/seld/signal/signal_handler.rs
+++ /dev/null
@@ -1,25 +0,0 @@
-//! ref: composer/vendor/seld/signal-handler/src/SignalHandler.php
-
-#[derive(Debug)]
-pub struct SignalHandler;
-
-// TODO(phase-c): disable signal handler at all for now.
-impl SignalHandler {
-    pub const SIGINT: &'static str = "SIGINT";
-    pub const SIGTERM: &'static str = "SIGTERM";
-    pub const SIGHUP: &'static str = "SIGHUP";
-
-    pub fn create(_signals: Vec<String>, _callback: Box<dyn Fn(String, &SignalHandler)>) -> Self {
-        Self
-    }
-
-    pub fn unregister(&self) {}
-
-    pub fn exit_with_last_signal(&self) {
-        std::process::exit(0);
-    }
-
-    pub fn is_triggered(&self) -> bool {
-        false
-    }
-}