refactor(app): migrate server lifecycle to Echo v5

- Add http.Server field to App struct for explicit server management
- Add StartServer() method to create and start HTTP server
- Replace echo.Close() with http.Server.Shutdown() in Shutdown()
- Update import from echo/v4 to echo/v5

Changes:
- New() initializes server field as nil
- StartServer() creates http.Server with Echo as handler
- Shutdown() uses http.Server.Shutdown() with context timeout
- Removed deprecated echo.Close() call (v5 API change)

This provides better control over server lifecycle and graceful shutdown.

internal/app/app.go

@@ -3,18 +3,20 @@ package app
 import (
 	"context"
 	"log"
+	"net/http"
 	"os"
 	"os/signal"
 	"sync"
 	"syscall"
 	"time"
 
-	"github.com/labstack/echo/v4"
+	"github.com/labstack/echo/v5"
 )
 
 // App manages application lifecycle and graceful shutdown
 type App struct {
 	echo            *echo.Echo
+	server          *http.Server
 	shutdownTimeout time.Duration
 	shutdownMutex   sync.Mutex
 	shutdownDone    chan struct{}
@@ -24,11 +26,28 @@ type App struct {
 func New(echo *echo.Echo) *App {
 	return &App{
 		echo:            echo,
+		server:          nil,
 		shutdownTimeout: 30 * time.Second,
 		shutdownDone:    make(chan struct{}),
 	}
 }
 
+func (a *App) StartServer(addr string) error {
+	a.server = &http.Server{
+		Addr:    addr,
+		Handler: a.echo,
+	}
+
+	// Start HTTP server in background
+	go func() {
+		if err := a.server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			log.Fatalf("Server failed to start: %v", err)
+		}
+	}()
+
+	return nil
+}
+
 // Start begins all background services and blocks until shutdown signal
 func (a *App) Start() error {
 	log.Println("Starting application lifecycle management...")
@@ -77,19 +96,17 @@ func (a *App) Shutdown() error {
 	// Channel to track shutdown completion
 	done := make(chan struct{})
 
-	// Perform shutdown in goroutine
-	go func() {
-		defer close(done)
+	log.Println("Stopping HTTP Server...")
+	if a.server != nil {
+		ctx, cancel := context.WithTimeout(context.Background(), a.shutdownTimeout)
+		defer cancel()
 
-		// Stop accepting new connections and shutdown HTTP server
-		log.Println("Stopping HTTP server...")
-		if err := a.echo.Close(); err != nil {
+		if err := a.server.Shutdown(ctx); err != nil {
 			log.Printf("Error stopping HTTP server: %v", err)
 		}
+	}
 
-		log.Println("All services stopped")
-	}()
-
+	log.Println("All services stopped")
 	// Wait for shutdown or timeout
 	select {
 	case <-done:

internal/app/app_test.go

@@ -4,7 +4,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/labstack/echo/v4"
+	"github.com/labstack/echo/v5"
 	"github.com/stretchr/testify/assert"
 )