Set a group member extension

ex is one complete string; the SDK does not merge JSON. Preserve other application modules' namespaces before writing.

import { setGroupMemberInfo } from '@/uni_modules/unix-openim-sdk'

const previous = JSON.parse(member.ex || '{}')

await setGroupMemberInfo({
  groupID,
  userID: 'user_b',
  ex: JSON.stringify({ ...previous, title: 'maintainer' }),
})

Preserve unknown fields in a versioned schema and keep the original value when parsing fails. Users allowed to view member profiles can see the extension; store no tokens or secrets.

After Promise success, merge onGroupMemberInfoChanged by groupID:userID.