refactor(admin/members): dedupe STATUS_LABELS + reactive row update

Promote inline STATUS_LABELS copies (admin/members/index.vue,
member/account.vue) into app/config/memberStatus.js, matching the
app/config/circles.js pattern. Drive admin/members/[id].vue status
select from the same constant — completes the alignment started in
441a5f5.

Use the softer member-facing copy as canonical: "Paused" / "Closed"
instead of "Suspended" / "Cancelled".

Also fix markSlackInvited's non-reactive Object.assign on a plain
object inside a useFetch array — replace with index-find + element
reassignment so the row UI refreshes without a manual reload.

app/pages/admin/members/[id].vue

@@ -63,10 +63,11 @@
               <div class="field">
                 <label>Status</label>
                 <select v-model="form.status">
-                  <option value="pending_payment">pending_payment</option>
-                  <option value="active">active</option>
-                  <option value="suspended">suspended</option>
-                  <option value="cancelled">cancelled</option>
+                  <option
+                    v-for="(label, value) in STATUS_LABELS"
+                    :key="value"
+                    :value="value"
+                  >{{ label }}</option>
                 </select>
               </div>
               <div class="field">
@@ -242,6 +243,7 @@
 
 <script setup>
 import { formatActivity } from '~/utils/activityText'
+import { STATUS_LABELS } from '~/config/memberStatus'
 
 definePageMeta({
   layout: "admin",