feat(lyra): 启动 HTTP 服务并添加示例接口

- 注册 GET /hello，使用统一响应结构并添加路由回归测试
- 使用 lyra.toml 配置 Gin 模式与监听地址，处理启动错误
- 明确 handler/service 业务分包约定并同步文档

go/projects/lyra/internal/router/router_test.go

@@ -0,0 +1,28 @@
+package router_test
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"lyra/internal/router"
+
+	"github.com/gin-gonic/gin"
+)
+
+func TestHelloRoute(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	engine := gin.New()
+	router.RegisterRoutes(engine)
+
+	recorder := httptest.NewRecorder()
+	engine.ServeHTTP(recorder, httptest.NewRequest(http.MethodGet, "/hello", nil))
+
+	if recorder.Code != http.StatusOK {
+		t.Fatalf("GET /hello status = %d, want %d", recorder.Code, http.StatusOK)
+	}
+	want := `{"success":true,"data":"Hello, World!"}`
+	if got := recorder.Body.String(); got != want {
+		t.Fatalf("GET /hello body = %q, want %q", got, want)
+	}
+}