fix: add Windows compatibility for signal handling

cmd/playground/main.go

@@ -55,9 +55,9 @@ Access the web UI at http://localhost:8080/playground (or your configured host:p
 		Run: func(cmd *cobra.Command, args []string) {
 			server := playground.NewServerWithRefresh(port, host, refreshCache)
 
-			// Handle interrupt signals (Ctrl+C, Ctrl+Z, SIGTERM)
+			// Handle interrupt signals
 			sigChan := make(chan os.Signal, 1)
-			signal.Notify(sigChan, os.Interrupt, syscall.SIGTERM, syscall.SIGTSTP)
+			setupSignalHandling(sigChan)
 
 			// Start server in goroutine
 			errChan := make(chan error, 1)
@@ -70,12 +70,7 @@ Access the web UI at http://localhost:8080/playground (or your configured host:p
 			// Wait for interrupt or error
 			select {
 			case sig := <-sigChan:
-				// Handle SIGTSTP (Ctrl+Z) - convert to graceful shutdown
-				if sig == syscall.SIGTSTP {
-					color.Yellow("\n🛑 Received suspend signal (Ctrl+Z), shutting down gracefully...")
-				} else {
-					color.Yellow("\n🛑 Received interrupt signal, shutting down...")
-				}
+				handleShutdownSignal(sig)
 				shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), 5*time.Second)
 				defer shutdownCancel()
 
@@ -138,3 +133,22 @@ func createRefreshCmd() *cobra.Command {
 	}
 }
 
+// Platform-specific signal handling
+func setupSignalHandling(sigChan chan<- os.Signal) {
+	// Windows doesn't have SIGTSTP, so we use a conditional build
+	signal.Notify(sigChan, os.Interrupt, syscall.SIGTERM)
+	// On Unix systems, SIGTSTP is also handled (see signal_unix.go)
+	notifyUNIXSignals(sigChan)
+}
+
+func handleShutdownSignal(sig os.Signal) {
+	msg := getShutdownMessage(sig)
+	color.Yellow("\n🛑 %s", msg)
+}
+
+// Stub functions - overridden on Unix systems
+var notifyUNIXSignals = func(sigChan chan<- os.Signal) {}
+var getShutdownMessage = func(sig os.Signal) string {
+	return "Received interrupt signal, shutting down..."
+}
+

cmd/playground/signal_unix.go

@@ -0,0 +1,23 @@
+// +build unix
+
+package main
+
+import (
+	"os"
+	"os/signal"
+	"syscall"
+)
+
+func init() {
+	// Override the Unix signal handling
+	notifyUNIXSignals = func(sigChan chan<- os.Signal) {
+		signal.Notify(sigChan, syscall.SIGTSTP)
+	}
+
+	getShutdownMessage = func(sig os.Signal) string {
+		if sig == syscall.SIGTSTP {
+			return "Received suspend signal (Ctrl+Z), shutting down gracefully..."
+		}
+		return "Received interrupt signal, shutting down..."
+	}
+}