add initial application structure with configuration, logging, and health check endpoints

internal/exception/handler.go

@@ -0,0 +1,14 @@
+package exception
+
+import (
+	"github.com/labstack/echo/v4"
+)
+
+func RegisterErrorHandler(e *echo.Echo) {
+	e.HTTPErrorHandler = func(err error, c echo.Context) {
+		_ = c.JSON(500, map[string]any{
+			"code":    "INTERNAL_ERROR",
+			"message": err.Error(),
+		})
+	}
+}