Add backend foundation and config-driven workbench

backend/cmd/api/main.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"context"
+	"log/slog"
+	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"cmr-backend/internal/app"
+)
+
+func main() {
+	ctx := context.Background()
+
+	cfg, err := app.LoadConfigFromEnv()
+	if err != nil {
+		slog.Error("load config failed", "error", err)
+		os.Exit(1)
+	}
+
+	application, err := app.New(ctx, cfg)
+	if err != nil {
+		slog.Error("create app failed", "error", err)
+		os.Exit(1)
+	}
+	defer application.Close()
+
+	server := &http.Server{
+		Addr:              cfg.HTTPAddr,
+		Handler:           application.Router(),
+		ReadHeaderTimeout: 5 * time.Second,
+	}
+
+	go func() {
+		slog.Info("api server started", "addr", cfg.HTTPAddr)
+		if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			slog.Error("server stopped unexpectedly", "error", err)
+			os.Exit(1)
+		}
+	}()
+
+	stop := make(chan os.Signal, 1)
+	signal.Notify(stop, syscall.SIGINT, syscall.SIGTERM)
+	<-stop
+
+	shutdownCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	if err := server.Shutdown(shutdownCtx); err != nil {
+		slog.Error("graceful shutdown failed", "error", err)
+		os.Exit(1)
+	}
+}