feat: Add SysInfoVer endpoint and AppService for version retrieval

service/app.go

@@ -0,0 +1,28 @@
+package service
+
+import (
+	"os"
+	"sync"
+)
+
+type AppService struct {
+}
+
+var version = ""
+
+var once = &sync.Once{}
+
+func (a *AppService) GetAppVersion() string {
+	if version != "" {
+		return version
+	}
+	once.Do(func() {
+		v, err := os.ReadFile("resources/version")
+		if err != nil {
+			return
+		}
+		version = string(v)
+
+	})
+	return version
+}