fix: add missing signal.Stop in suspendProcess to prevent signal channel leak (Closes #1673) (#1674)

Each Ctrl+Z suspend call registered a SIGCONT channel via signal.Notify
but never called signal.Stop after receiving the signal. This caused a
signal channel leak on every suspend/resume cycle.

All other signal handlers in the codebase (handleSignals in tea.go and
listenForResize in signals_unix.go) correctly defer signal.Stop.

Signed-off-by: Cocoon-Break <54054995+kuishou68@users.noreply.github.com>

Author: kuishou68

tty_unix.go

@@ -40,6 +40,7 @@ const suspendSupported = true
 func suspendProcess() {
 	c := make(chan os.Signal, 1)
 	signal.Notify(c, syscall.SIGCONT)
+	defer signal.Stop(c)
 	_ = syscall.Kill(0, syscall.SIGTSTP)
 	// blocks until a CONT happens...
 	<-c