Make relay opt-in when pairing devices (#2706)

* feat: make relay opt-in for device pairing

* fix(relay): keep pairing state authoritative

* fix(relay): refresh pairing state across transports

* fix(onboard): honor explicit relay opt-out

* fix(relay): surface transport startup failures

* fix(pairing): gate offers for older daemons

* test(cli): rely on real pairing transport coverage

* fix(cli): report live relay without a pid file

* fix(relay): synchronize config during daemon startup

* fix(relay): preserve mutability for ignored overrides

* fix(cli): use reachable daemon for pairing

* fix(app): redirect invalid pair device routes

* fix(pairing): support remote host device pairing

Keep Pair Device host-relative through the existing settings and daemon RPC flow. Route CLI output through an injected adapter so workflow tests do not mutate process globals.

* fix(pairing): validate pairing destinations

Expose the host-relative Pair Device flow on every supported app platform. Reject a reachable daemon whose identity does not match the requested Paseo home before reading or mutating its pairing state.

* fix(pairing): render QR codes across platforms

Generate SVG text without DOM or canvas and render it through the existing cross-platform SVG stack.

* fix(cli): pair from persisted relay state

Allow explicit relay pairing while the daemon is stopped when relay is already enabled in persisted configuration.

packages/app/src/i18n/resources/zh-CN.ts

@@ -1403,9 +1403,20 @@ export const zhCN: TranslationResources = {
       loadingOffer: "正在加载配对 offer...",
       failedToLoadOffer: "加载配对 offer 失败。",
       relayDisabled: "Relay 未启用。启用 relay 后才能配对设备。",
+      enableTitle: "启用中继？",
+      enableDescription: "中继让此设备可以从任何地方连接。配对流量采用端到端加密。",
+      relayDocs: "中继如何工作",
+      relayDocsAccessibility: "阅读 Paseo 中继的工作原理",
+      enableRelay: "启用中继",
+      enablingRelay: "正在启用...",
+      notNow: "暂不",
+      directConnectionHint:
+        "不使用中继时，请通过 TCP、Tailscale 或其他 VPN 直接连接。不会生成二维码。",
+      updateRequired: "请更新主机，以便从 Paseo Desktop 启用中继。",
       unavailable: "配对 offer 不可用。",
       hint: "用手机上的 Paseo 扫描此二维码，或复制下方链接。",
       qrUnavailable: "二维码不可用。",
+      qrAccessibility: "配对二维码",
       retry: "重试",
       copy: "复制",
       copied: "已复制",