Refactor core configuration and UUID handling

- Changed UUIDLength type from byte to int in core/config/consts.go
- Introduced MetaDir constant in core/config/consts.go
- Added corestate package with initial state management and UUID handling
- Implemented GetNodeUUID and SetNodeUUID functions for UUID file management
- Created RunManager and RunFileManager for runtime directory management
- Updated GeneralServer to use new configuration structure
- Removed deprecated init package and replaced with main entry point
- Added color utility functions for logging
- Enhanced UUID generation functions in utils package
- Updated update logic to handle new configuration structure
- Added routines for cleaning temporary runtime directories
- Introduced response formatting for API responses

core/corestate/node_uuid.go

@@ -0,0 +1,80 @@
+package corestate
+
+import (
+	"encoding/hex"
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/akyaiy/GoSally-mvp/core/config"
+	"github.com/akyaiy/GoSally-mvp/core/utils"
+)
+
+// GetNodeUUID outputs the correct uuid from the file at the path specified in the arguments.
+// If the uuid is not correct or is not exist, an empty string and an error will be returned.
+// The path to the identifier must contain the path to the "uuid" directory,
+// not the file with the identifier itself, for example: "uuid/data"
+func GetNodeUUID(metaInfPath string) (string, error) {
+	uuid, err := readNodeUUIDRaw(filepath.Join(metaInfPath, "data"))
+	if err != nil {
+		return "", err
+	}
+	return hex.EncodeToString(uuid[:]), nil
+}
+
+func readNodeUUIDRaw(p string) ([]byte, error) {
+	data, err := os.ReadFile(p)
+	if err != nil {
+		return data, err
+	}
+	if len(data) != config.GetInternalConsts().GetUUIDLength() {
+		return data, errors.New("decoded UUID length mismatch")
+	}
+	return data, nil
+}
+
+// SetNodeUUID sets the identifier to the given path.
+// The function replaces the identifier's associated directory with all its contents.
+func SetNodeUUID(metaInfPath string) error {
+	if !strings.HasSuffix(metaInfPath, "uuid") {
+		return errors.New("invalid meta/uuid path")
+	}
+	info, err := os.Stat(metaInfPath)
+	if err == nil && info.IsDir() {
+		err = os.RemoveAll(metaInfPath)
+		if err != nil {
+			return err
+		}
+	} else if err != nil && !os.IsNotExist(err) {
+		return err
+	}
+
+	err = os.MkdirAll(metaInfPath, 0755)
+	if err != nil {
+		return err
+	}
+	dataPath := filepath.Join(metaInfPath, "data")
+
+	uuidStr, err := utils.NewUUID32Raw()
+	if err != nil {
+		return err
+	}
+
+	err = os.WriteFile(dataPath, uuidStr[:], 0644)
+	if err != nil {
+		return err
+	}
+
+	readmePath := filepath.Join(metaInfPath, "README.txt")
+	readmeContent := ` - - - - ! STRICTLY FORBIDDEN TO MODIFY THIS DIRECTORY ! - - - - 
+This directory contains the unique node identifier stored in the file named data.
+This identifier is critical for correct node recognition both locally and across the network.
+Any modification, deletion, or tampering with this directory may lead to permanent loss of identity, data corruption, or network conflicts.
+Proceed at your own risk. You have been warned.`
+	err = os.WriteFile(readmePath, []byte(readmeContent), 0644)
+	if err != nil {
+		return err
+	}
+	return nil
+}