feat(chat): copy, add-to-contacts, and new-message toast (Q2/Q3/Q4)

- Q3: copy the peer z-address from the thread header (SmallButton), and right-click
  any message to copy its body.
- Q2: an "Add contact" action in the header when the peer isn't already known —
  one click saves them to the address book (rename later in Contacts).
- Q4: capture ChatService::ingest's new-message count (previously discarded) and
  fire an in-app toast when new encrypted chat arrives while the user isn't on the
  Chat tab (main-thread MainCb sites only).

i18n (EN + 8 languages, additive; no new CJK glyphs).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

res/lang/de.json

@@ -135,12 +135,15 @@
     "change_pass_title": "Passphrase ändern",
     "characters": "Zeichen",
     "chat": "Chat",
+    "chat_add_contact": "Kontakt hinzufügen",
     "chat_cancel": "Abbrechen",
+    "chat_contact_added": "Kontakt hinzugefügt – benenne ihn in Kontakte um",
     "chat_contact_request": "kontaktanfrage",
     "chat_empty_hint": "Noch keine Unterhaltungen. Nachrichten, die du erhältst, erscheinen hier.",
     "chat_locked_hint": "Entsperre deine Wallet, um deine Chats zu laden.",
     "chat_new_button": "Neue Unterhaltung",
     "chat_new_message": "Nachricht",
+    "chat_new_message_toast": "Neue verschlüsselte Chat-Nachricht",
     "chat_new_send": "Anfrage senden",
     "chat_new_title": "Neue Unterhaltung",
     "chat_new_zaddr": "z-Adresse des Empfängers",

res/lang/es.json

@@ -135,12 +135,15 @@
     "change_pass_title": "Cambiar frase de contraseña",
     "characters": "caracteres",
     "chat": "Chat",
+    "chat_add_contact": "Añadir contacto",
     "chat_cancel": "Cancelar",
+    "chat_contact_added": "Contacto añadido: renómbralo en Contactos",
     "chat_contact_request": "solicitud de contacto",
     "chat_empty_hint": "Aún no hay conversaciones. Los mensajes que recibas aparecerán aquí.",
     "chat_locked_hint": "Desbloquea tu monedero para cargar tus chats.",
     "chat_new_button": "Nueva conversación",
     "chat_new_message": "Mensaje",
+    "chat_new_message_toast": "Nuevo mensaje de chat cifrado",
     "chat_new_send": "Enviar solicitud",
     "chat_new_title": "Nueva conversación",
     "chat_new_zaddr": "Dirección z del destinatario",

res/lang/fr.json

@@ -135,12 +135,15 @@
     "change_pass_title": "Changer la phrase secrète",
     "characters": "caractères",
     "chat": "Discussion",
+    "chat_add_contact": "Ajouter un contact",
     "chat_cancel": "Annuler",
+    "chat_contact_added": "Contact ajouté — renommez-le dans Contacts",
     "chat_contact_request": "demande de contact",
     "chat_empty_hint": "Aucune conversation pour l'instant. Les messages que vous recevez apparaîtront ici.",
     "chat_locked_hint": "Déverrouillez votre portefeuille pour charger vos discussions.",
     "chat_new_button": "Nouvelle conversation",
     "chat_new_message": "Message",
+    "chat_new_message_toast": "Nouveau message chiffré",
     "chat_new_send": "Envoyer la demande",
     "chat_new_title": "Nouvelle conversation",
     "chat_new_zaddr": "Adresse Z du destinataire",

res/lang/ja.json

@@ -135,12 +135,15 @@
     "change_pass_title": "パスフレーズを変更",
     "characters": "文字",
     "chat": "チャット",
+    "chat_add_contact": "連絡先に追加",
     "chat_cancel": "キャンセル",
+    "chat_contact_added": "連絡先を追加しました — 連絡先で名前を変更できます",
     "chat_contact_request": "連絡リクエスト",
     "chat_empty_hint": "まだ会話はありません。受信したメッセージはここに表示されます。",
     "chat_locked_hint": "チャットを読み込むにはウォレットのロックを解除してください。",
     "chat_new_button": "新しい会話",
     "chat_new_message": "メッセージ",
+    "chat_new_message_toast": "新しい暗号化チャットメッセージ",
     "chat_new_send": "リクエストを送信",
     "chat_new_title": "新しい会話",
     "chat_new_zaddr": "宛先Zアドレス",

res/lang/ko.json

@@ -135,12 +135,15 @@
     "change_pass_title": "암호 변경",
     "characters": "문자",
     "chat": "채팅",
+    "chat_add_contact": "연락처 추가",
     "chat_cancel": "취소",
+    "chat_contact_added": "연락처 추가됨 — 연락처에서 이름을 변경하세요",
     "chat_contact_request": "연락 요청",
     "chat_empty_hint": "아직 대화가 없습니다. 받은 메시지가 여기에 표시됩니다.",
     "chat_locked_hint": "채팅을 불러오려면 지갑 잠금을 해제하세요.",
     "chat_new_button": "새 대화",
     "chat_new_message": "메시지",
+    "chat_new_message_toast": "새 암호화 채팅 메시지",
     "chat_new_send": "요청 보내기",
     "chat_new_title": "새 대화",
     "chat_new_zaddr": "받는 사람 z-주소",

res/lang/pt.json

@@ -135,12 +135,15 @@
     "change_pass_title": "Alterar senha",
     "characters": "caracteres",
     "chat": "Chat",
+    "chat_add_contact": "Adicionar contato",
     "chat_cancel": "Cancelar",
+    "chat_contact_added": "Contato adicionado — renomeie em Contatos",
     "chat_contact_request": "solicitação de contato",
     "chat_empty_hint": "Nenhuma conversa ainda. As mensagens que você receber aparecerão aqui.",
     "chat_locked_hint": "Desbloqueie sua carteira para carregar suas conversas.",
     "chat_new_button": "Nova conversa",
     "chat_new_message": "Mensagem",
+    "chat_new_message_toast": "Nova mensagem de chat criptografada",
     "chat_new_send": "Enviar solicitação",
     "chat_new_title": "Nova conversa",
     "chat_new_zaddr": "Endereço-z do destinatário",

res/lang/ru.json

@@ -135,12 +135,15 @@
     "change_pass_title": "Сменить пароль",
     "characters": "символов",
     "chat": "Чат",
+    "chat_add_contact": "Добавить контакт",
     "chat_cancel": "Отмена",
+    "chat_contact_added": "Контакт добавлен — переименуйте его в Контактах",
     "chat_contact_request": "запрос контакта",
     "chat_empty_hint": "Пока нет переписок. Полученные сообщения появятся здесь.",
     "chat_locked_hint": "Разблокируйте кошелёк, чтобы загрузить переписку.",
     "chat_new_button": "Новая переписка",
     "chat_new_message": "Сообщение",
+    "chat_new_message_toast": "Новое зашифрованное сообщение",
     "chat_new_send": "Отправить запрос",
     "chat_new_title": "Новая переписка",
     "chat_new_zaddr": "Z-адрес получателя",

res/lang/zh.json

@@ -135,12 +135,15 @@
     "change_pass_title": "更改密码短语",
     "characters": "字符",
     "chat": "聊天",
+    "chat_add_contact": "添加联系人",
     "chat_cancel": "取消",
+    "chat_contact_added": "已添加联系人——可在联系人中重命名",
     "chat_contact_request": "联系人请求",
     "chat_empty_hint": "暂无对话。您收到的消息将显示在此处。",
     "chat_locked_hint": "解锁钱包以加载您的聊天记录。",
     "chat_new_button": "新建对话",
     "chat_new_message": "消息",
+    "chat_new_message_toast": "新的加密聊天消息",
     "chat_new_send": "发送请求",
     "chat_new_title": "新建对话",
     "chat_new_zaddr": "收款方 z 地址",