fix rewrite omitting trailing slash, error msg update

internal/route/provider/provider.go

@@ -109,7 +109,7 @@ func (p *Provider) startRoute(parent task.Parent, r *R.Route) E.Error {
 	return nil
 }
 
-// Start implements*task.TaskStarter.
+// Start implements task.TaskStarter.
 func (p *Provider) Start(parent task.Parent) E.Error {
 	t := parent.Subtask("provider."+p.name, false)
 

internal/route/rules/validate.go

@@ -54,10 +54,14 @@ func validateURLPath(args []string) (any, E.Error) {
 		return nil, ErrExpectOneArg
 	}
 	p := args[0]
+	trailingSlash := len(p) > 1 && p[len(p)-1] == '/'
 	p, _, _ = strings.Cut(p, "#")
 	p = path.Clean(p)
 	if len(p) == 0 {
-		return "/", nil
+		return nil, ErrInvalidArguments.Withf("empty path")
+	}
+	if trailingSlash {
+		p += "/"
 	}
 	if p[0] != '/' {
 		return nil, ErrInvalidArguments.Withf("must start with /")