feat: scaffold go backend foundation

internal/app/server.go

@@ -0,0 +1,19 @@
+package app
+
+import (
+	"net/http"
+
+	"tutor/internal/config"
+	"tutor/internal/httpapi"
+	"tutor/internal/workflows"
+)
+
+func NewServer(cfg config.Config) *http.Server {
+	runner := workflows.NewStubRunner()
+	handler := httpapi.NewHandler(cfg, runner)
+
+	return &http.Server{
+		Addr:    cfg.HTTPAddr,
+		Handler: handler.Routes(),
+	}
+}