insert copyright headers for images

test/i18n.test.js

@@ -13,7 +13,7 @@ test('German legal pages and contacts remain static when the app uses English',
   const i18n = await loadI18n(context);
   const html = await fs.readFile(path.join(root, 'public/index.html'), 'utf8');
   const englishHtml = localizeHtml(html, key => i18n.t(key));
-  for (const name of ['privacy', 'imprint']) {
+  for (const name of ['privacy', 'imprint', 'terms']) {
     const pattern = new RegExp(`<article[^>]+data-info-page="${name}"[^>]*>[\\s\\S]*?</article>`);
     const page = pattern.exec(html)?.[0];
     assert.ok(page, name);
@@ -22,7 +22,7 @@ test('German legal pages and contacts remain static when the app uses English',
     assert.equal(pattern.exec(englishHtml)?.[0], page);
   }
   for (const catalog of context.Wegwichtel.TextCatalogs.values()) {
-    for (const key of ['privacy', 'imprint', 'contacts']) {
+    for (const key of ['privacy', 'imprint', 'terms', 'contacts']) {
       assert.equal(Object.hasOwn(catalog, key), false, key);
     }
   }