add new functionality and improve backend server structure

- Enhance server functionality and optimize backend code
- Add multi-database support (PostgreSQL, MySQL, SQLite)

server/core_backend-server/tools/osutils/run.go

@@ -0,0 +1,32 @@
+package osutils
+
+import (
+	"os"
+	"strings"
+)
+
+var runDirs = []string{os.TempDir(), cacheDir()}
+
+// IsProbablyGoRun loosely checks if the current program was started with "go run".
+func IsProbablyGoRun() bool {
+	for _, dir := range runDirs {
+		if dir != "" && strings.HasPrefix(os.Args[0], dir) {
+			return true
+		}
+	}
+
+	return false
+}
+
+func cacheDir() string {
+	dir := os.Getenv("GOCACHE")
+	if dir == "off" {
+		return ""
+	}
+
+	if dir == "" {
+		dir, _ = os.UserCacheDir()
+	}
+
+	return dir
+}