add cross-platform interrupt signal utility

process/interrupt_unix.go

@@ -0,0 +1,13 @@
+//go:build !windows
+
+package process
+
+import "os"
+
+// SendInterrupt sends an interrupt signal to the current process.
+// On Unix systems, this sends os.Interrupt (SIGINT).
+func SendInterrupt() {
+	if p, err := os.FindProcess(os.Getpid()); err == nil {
+		_ = p.Signal(os.Interrupt)
+	}
+}

process/interrupt_unix_test.go

@@ -0,0 +1,27 @@
+//go:build !windows
+
+package process
+
+import (
+	"os"
+	"os/signal"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestSendInterrupt(t *testing.T) {
+	sigChan := make(chan os.Signal, 1)
+	signal.Notify(sigChan, os.Interrupt)
+	defer signal.Stop(sigChan)
+
+	SendInterrupt()
+
+	select {
+	case sig := <-sigChan:
+		require.Equal(t, os.Interrupt, sig)
+	case <-time.After(2 * time.Second):
+		t.Fatal("timeout waiting for interrupt signal")
+	}
+}

process/interrupt_windows.go

@@ -0,0 +1,24 @@
+//go:build windows
+
+package process
+
+import (
+	"os"
+	"syscall"
+)
+
+var (
+	kernel32                     = syscall.NewLazyDLL("kernel32.dll")
+	procGenerateConsoleCtrlEvent = kernel32.NewProc("GenerateConsoleCtrlEvent")
+)
+
+// SendInterrupt sends an interrupt signal to the current process.
+// On Windows, this uses GenerateConsoleCtrlEvent with CTRL_BREAK_EVENT
+// because Go's p.Signal(os.Interrupt) is not implemented on Windows.
+func SendInterrupt() {
+	// Send CTRL_BREAK_EVENT to current process's process group
+	// Using os.Getpid() targets only processes in our group (typically just us in production)
+	// This avoids sending to all console processes (group 0) which would kill parent processes
+	pid := os.Getpid()
+	procGenerateConsoleCtrlEvent.Call(syscall.CTRL_BREAK_EVENT, uintptr(pid))
+}

process/interrupt_windows_test.go

@@ -0,0 +1,20 @@
+//go:build windows
+
+package process
+
+import "testing"
+
+func TestSendInterrupt(t *testing.T) {
+	// On Windows CI (GitHub Actions), GenerateConsoleCtrlEvent may not work
+	// as expected without a proper console attached.
+	// This test verifies the function doesn't panic and the syscall loads correctly.
+	defer func() {
+		if r := recover(); r != nil {
+			t.Fatalf("SendInterrupt panicked: %v", r)
+		}
+	}()
+
+	// Just verify it doesn't crash - the actual signal delivery
+	// depends on console configuration which varies in CI
+	SendInterrupt()
+}