feat: implement build-time version injection

- Replace hardcoded version with build-time injected variables
- Add version, commit, and date variables to main.go with default values
- Update Makefile ldflags to use consistent variable names
- Add detailed 'version' subcommand showing build info, Go version, and platform
- Maintain compatibility with existing release workflow
- Support both --version flag (simple) and version subcommand (detailed)

Makefile

@@ -26,7 +26,7 @@ BUILD_TIME=$(shell date -u '+%Y-%m-%d_%H:%M:%S')
 COMMIT=$(shell git rev-parse --short HEAD 2>/dev/null || echo "unknown")
 
 # Linker flags
-LDFLAGS=-X main.Version=$(VERSION) -X main.BuildTime=$(BUILD_TIME) -X main.Commit=$(COMMIT)
+LDFLAGS=-X main.version=$(VERSION) -X main.date=$(BUILD_TIME) -X main.commit=$(COMMIT)
 
 all: check build
 

cmd/soundtouch-cli/common.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"net"
+	"runtime"
 	"strconv"
 	"strings"
 	"time"
@@ -146,3 +147,14 @@ func PrintError(message string) {
 func PrintWarning(message string) {
 	fmt.Printf("⚠️  %s\n", message)
 }
+
+// showVersionInfo displays detailed version information including build details
+func showVersionInfo(_ *cli.Context) error {
+	fmt.Printf("soundtouch-cli version %s\n", version)
+	fmt.Printf("Build commit: %s\n", commit)
+	fmt.Printf("Build date: %s\n", date)
+	fmt.Printf("Go version: %s\n", runtime.Version())
+	fmt.Printf("Platform: %s/%s\n", runtime.GOOS, runtime.GOARCH)
+
+	return nil
+}

cmd/soundtouch-cli/main.go

@@ -7,6 +7,13 @@ import (
 	"github.com/urfave/cli/v2"
 )
 
+// Build-time variables injected via ldflags
+var (
+	version = "dev"
+	commit  = "unknown"
+	date    = "unknown"
+)
+
 func main() {
 	app := &cli.App{
 		Name:  "soundtouch-cli",
@@ -14,7 +21,7 @@ func main() {
 		Description: `A comprehensive CLI tool for interacting with Bose SoundTouch devices.
    Supports device discovery, playback control, volume/bass/balance adjustment,
    source selection, zone management, and more.`,
-		Version: "1.0.0",
+		Version: version,
 		Authors: []*cli.Author{
 			{
 				Name:  "SoundTouch CLI Contributors",
@@ -23,6 +30,13 @@ func main() {
 		},
 		Flags: CommonFlags,
 		Commands: []*cli.Command{
+			// Version commands
+			{
+				Name:    "version",
+				Aliases: []string{"v"},
+				Usage:   "Show detailed version information",
+				Action:  showVersionInfo,
+			},
 			// Discovery commands
 			{
 				Name:    "discover",