legal: add AGPL-3.0 license, copyright headers, commercial license info

- LICENSE: GNU AGPL-3.0 (full text)
- Copyright headers added to all 19 source files (TS + Vue)
- COMMERCIAL_LICENSE.md: dual-license explanation (AGPL + commercial)

src/router/index.ts

@@ -1,3 +1,18 @@
+// racecraft — Vue.js web client for sim racing telemetry analysis
+// Copyright (C) 2026  Jan-Peter v. Hunnius
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero 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 Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
 import { createRouter, createWebHistory } from 'vue-router'
 
 const router = createRouter({