chore: support version flag (#3)

Author: jialeicui

Makefile

@@ -1,2 +1,5 @@
+VERSION ?= $(shell git describe --tags --abbrev=0 2>/dev/null || echo "dev")
+COMMIT ?= $(shell git rev-parse --short HEAD 2>/dev/null || echo "unknown")
+
 build:
-	@go build -o keyswift cmd/keyswift/main.go
+	@go build -ldflags "-X main.version=$(VERSION) -X main.commit=$(COMMIT)" -o keyswift cmd/keyswift/main.go

cmd/keyswift/main.go

@@ -25,11 +25,23 @@ var (
 	flagConfig           = flag.String("config", "", "Configuration file path (defaults to $XDG_CONFIG_HOME/keyswift/config.js)")
 	flagVerbose          = flag.Bool("verbose", false, "Enable verbose logging")
 	flagOutputDeviceName = flag.String("output-device-name", "keyswift", "Name of the virtual keyboard device")
+	flagVersion          = flag.Bool("version", false, "Print version information and exit")
+)
+
+// These variables are injected at compile time
+var (
+	version = "dev"
+	commit  = "unknown"
 )
 
 func main() {
 	flag.Parse()
 
+	if *flagVersion {
+		fmt.Printf("keyswift version %s (commit: %s)\n", version, commit)
+		os.Exit(0)
+	}
+
 	// Configure logging
 	if *flagVerbose {
 		slog.SetDefault(slog.New(slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{