feat(i18n): add "unknown" translation placeholder to multiple locales

Add "[to be translated]:Unknown" placeholder for the "unknown" key in various language files to mark it for future translation.

src/renderer/src/i18n/locales/zh-tw.json

@@ -1036,6 +1036,7 @@
     "success": "成功",
     "swap": "交換",
     "topics": "話題",
+    "unknown": "[to be translated]:Unknown",
     "unnamed": "未命名",
     "update_success": "更新成功",
     "upload_files": "上傳檔案",

src/renderer/src/i18n/translate/el-gr.json

@@ -1036,6 +1036,7 @@
     "success": "Επιτυχία",
     "swap": "Εναλλαγή",
     "topics": "Θέματα",
+    "unknown": "[to be translated]:Unknown",
     "unnamed": "Χωρίς όνομα",
     "update_success": "Επιτυχής ενημέρωση",
     "upload_files": "Ανέβασμα αρχείου",

src/renderer/src/i18n/translate/es-es.json

@@ -1036,6 +1036,7 @@
     "success": "Éxito",
     "swap": "Intercambiar",
     "topics": "Temas",
+    "unknown": "[to be translated]:Unknown",
     "unnamed": "Sin nombre",
     "update_success": "Actualización exitosa",
     "upload_files": "Subir archivo",

src/renderer/src/i18n/translate/fr-fr.json

@@ -1036,6 +1036,7 @@
     "success": "Succès",
     "swap": "Échanger",
     "topics": "Sujets",
+    "unknown": "[to be translated]:Unknown",
     "unnamed": "Sans nom",
     "update_success": "Mise à jour réussie",
     "upload_files": "Uploader des fichiers",

src/renderer/src/i18n/translate/ja-jp.json

@@ -1036,6 +1036,7 @@
     "success": "成功",
     "swap": "交換",
     "topics": "トピック",
+    "unknown": "[to be translated]:Unknown",
     "unnamed": "無題",
     "update_success": "更新成功",
     "upload_files": "ファイルをアップロードする",

src/renderer/src/i18n/translate/pt-pt.json

@@ -1036,6 +1036,7 @@
     "success": "Sucesso",
     "swap": "Trocar",
     "topics": "Tópicos",
+    "unknown": "[to be translated]:Unknown",
     "unnamed": "Sem nome",
     "update_success": "Atualização bem-sucedida",
     "upload_files": "Carregar arquivo",

src/renderer/src/i18n/translate/ru-ru.json

@@ -1036,6 +1036,7 @@
     "success": "Успешно",
     "swap": "Поменять местами",
     "topics": "Топики",
+    "unknown": "[to be translated]:Unknown",
     "unnamed": "Без имени",
     "update_success": "Обновление выполнено успешно",
     "upload_files": "Загрузить файл",