Outbounds: Outbound: add license header

Signed-off-by: Vasiliy Doylov <nekocwd@mainlining.org>

src/logic/outbounds/outbound.vala

@@ -1,3 +1,22 @@
+/* outbound.vala
+ *
+ * Copyright 2025 Vasiliy Doylov (NekoCWD) <nekocwd@mainlining.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
 class Singularity.Outbound.Outbound : Object, Json.Serializable {
     // We can't use name `type` in vala
     public string type_name { get; construct set; default = ""; }