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/app/app.go

@@ -0,0 +1,64 @@
+package app
+
+import (
+	"context"
+	"log"
+	"log/slog"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"github.com/akyaiy/GoSally-mvp/core/config"
+	"github.com/akyaiy/GoSally-mvp/core/corestate"
+	"github.com/akyaiy/GoSally-mvp/core/update"
+)
+
+type AppContract interface {
+	InitialHooks(fn ...func(cs *corestate.CoreState, x *AppX))
+	Run(fn func(ctx context.Context, cs *corestate.CoreState, x *AppX) error)
+}
+
+type App struct {
+	initHooks []func(cs *corestate.CoreState, x *AppX)
+	runHook   func(ctx context.Context, cs *corestate.CoreState, x *AppX) error
+
+	Corestate *corestate.CoreState
+	AppX      *AppX
+}
+
+type AppX struct {
+	Config  *config.Compositor
+	Log     *log.Logger
+	SLog    *slog.Logger
+	Updated *update.Updater
+}
+
+func New() AppContract {
+	return &App{
+		AppX: &AppX{
+			Log: log.Default(),
+		},
+		Corestate: &corestate.CoreState{},
+	}
+}
+
+func (a *App) InitialHooks(fn ...func(cs *corestate.CoreState, x *AppX)) {
+	a.initHooks = append(a.initHooks, fn...)
+}
+
+func (a *App) Run(fn func(ctx context.Context, cs *corestate.CoreState, x *AppX) error) {
+	a.runHook = fn
+
+	for _, hook := range a.initHooks {
+		hook(a.Corestate, a.AppX)
+	}
+
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGINT, syscall.SIGTERM, syscall.SIGQUIT)
+	defer stop()
+
+	if a.runHook != nil {
+		if err := a.runHook(ctx, a.Corestate, a.AppX); err != nil {
+			log.Fatalf("fatal in Run: %v", err)
+		}
+	}
+}