fix(app): add missing i18n keys for host settings (#1478)

* fix(app): add missing i18n keys for host settings

The client UI i18n migration (#1282) referenced translation keys that
were never added to any locale file, so i18next rendered the raw key
string in Settings → Host (e.g. a button labeled
"settings.host.daemon.restart.confirm").

Add the six missing keys to all six locales with real translations:
- settings.host.daemon.rename.submit
- settings.host.daemon.restart.confirm
- settings.host.orchestration.systemPrompt.{edit,reset,save,saving}

The seventh broken reference, in pair-device-modal.tsx, used the wrong
namespace (settings.integrations.pairDevices.rowTitle); the key is
defined at settings.host.pairDevices.rowTitle. Point the reference there.

Reported in https://github.com/getpaseo/paseo/pull/1282#issuecomment-4686672699

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

* fix(app): correct machine-translated Save/Saving labels (es/fr/ar)

#1282 left several Save/Saving labels machine-translated into the
"economize money" sense rather than the persist-data sense, so users saw
"Ahorro..." (es), "Économie..." (fr), and "توفير..." (ar) where "Saving..."
was meant.

Fix renameModal.saving and settings.project.actions.{save,saving} in the
three affected locales. ar's actions.save also moves from the conjugated
"يحفظ" to the standard button form "حفظ". Wording matches each locale's
already-correct siblings (e.g. es "Proyecto guardado") and the keys added
in the previous commit. ru and zh-CN were already correct and are untouched.

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

---------

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

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

@@ -1593,6 +1593,10 @@ export const zhCN: TranslationResources = {
           sheetTitle: "追加 system prompt",
           accessibilityLabel: "追加 system prompt",
           placeholder: "始终保持回复简洁。",
+          edit: "编辑",
+          reset: "重置",
+          save: "保存",
+          saving: "保存中...",
         },
       },
       agents: {
@@ -1606,10 +1610,12 @@ export const zhCN: TranslationResources = {
           editLabel: "编辑标签",
           title: "重命名 Host",
           placeholder: "我的 Host",
+          submit: "重命名",
         },
         restart: {
           title: "重启 Daemon",
           hint: "重启 Daemon 进程。应用会自动重新连接",
+          confirm: "重启",
           confirmTitle: "重启 {{name}}",
           confirmMessage: "这会重启 Daemon。其上运行的 Agent 会继续运行；应用会自动重新连接。",
           restarting: "正在重启...",