fix(devices): unicode escape bug + onSuccess race + en locale + apiErr surface

Code-review follow-up on 321c65b.

- prettier ate the raw glyphs (✓/✕/✏️) in AdminUserDetail.tsx and emitted
  \u2713 / \u2715 / \u270F\uFE0F as JSX text children. JSX does NOT
  process \u… escapes inside element children, so admin users saw the
  literal six-character strings on Save/Cancel/Rename buttons. Wrap each
  glyph in a JS expression {'…'} so it survives both prettier and JSX.
- renameDeviceMutation.onSuccess on Subscription.tsx no longer
  unconditionally clears the edit state. If the user already navigated
  to a different device while the previous save was in flight, we keep
  their in-progress input. Same shape applied to AdminUserDetail.tsx —
  the alias is snapshot before the await so a race can't smuggle the
  wrong value into the request, and the post-success reset is guarded.
- AdminUserDetail rename error path now surfaces the backend's
  response.data.detail (e.g. '64-char limit' message) instead of the
  generic localized userActions.error toast.
- Add the new rename i18n keys to src/locales/en.json so English users
  no longer fall back to Russian labels. ua/zh/fa to follow in a
  dedicated translation pass.

src/locales/en.json

@@ -468,6 +468,11 @@
     "confirmDeleteAllDevices": "Delete all devices?",
     "deviceDeleted": "Device deleted",
     "allDevicesDeleted": "All devices deleted",
+    "renameDevice": "Rename",
+    "renameDeviceSave": "Save",
+    "renameDeviceCancel": "Cancel",
+    "renameDevicePlaceholder": "Device name",
+    "deviceRenamed": "Device name updated",
     "platform": "Platform",
     "model": "Model",
     "connectedAt": "Connected",
@@ -3176,7 +3181,10 @@
           "none": "No connected devices",
           "resetAll": "Reset all",
           "deleted": "Device removed",
-          "allDeleted": "All devices reset"
+          "allDeleted": "All devices reset",
+          "rename": "Rename",
+          "renameSave": "Save",
+          "renamed": "Device name updated"
         },
         "referral": {
           "title": "Referral program",