feat: Add audit logging (#38189)

Co-authored-by: bircni <bircni@users.noreply.github.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

services/audit/export.go

@@ -0,0 +1,25 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package audit
+
+import (
+	"io"
+
+	audit_model "gitea.dev/models/audit"
+	"gitea.dev/modules/json"
+)
+
+// WriteEventsAsJSON writes one JSON object per line.
+func WriteEventsAsJSON(w io.Writer, events []*audit_model.Event) error {
+	for _, event := range events {
+		b, err := json.Marshal(event)
+		if err != nil {
+			return err
+		}
+		if _, err := w.Write(append(b, '\n')); err != nil {
+			return err
+		}
+	}
+	return nil
+}