feat(orbit): show track attribution in host queue + host label in guest queue

Before: the guest queue already labelled guest-suggested tracks with
"Suggested by {user}", but host picks had no label — and the host's own
queue had no attribution at all. The host couldn't tell which upcoming
rows came from guests without checking the pending-approvals list.

- Guest queue: host-pick rows now show "Added by host" instead of hiding
  the attribution line.
- Host queue: each row (and the current track) shows "Added by you" or
  "Added by {user}" while an Orbit session is active. Lookup uses the
  existing OrbitState.queue / currentTrack addedBy field, so no new
  protocol fields.

New i18n keys (en+de+fr+nl+zh+nb+ru+es):
  orbit.queueAddedByHost · queueAddedByYou · queueAddedByUser

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/locales/zh.ts

@@ -1624,6 +1624,9 @@ export const zhTranslation = {
     approvalDecline: '拒绝',
     guestUpNextMore: '+ 主持人队列中还有 {{count}} 首',
     guestSubmitter: '来自 {{user}}',
+    queueAddedByHost: '由主持人添加',
+    queueAddedByYou: '由你添加',
+    queueAddedByUser: '由 {{user}} 添加',
     guestEmpty: '还没有建议。打开曲目的上下文菜单并选择"添加到 Orbit 会话"。',
     guestFooter: '主持人控制播放 — 你无法更改列表。',
     exitKickedTitle: '你已被会话封禁',