feat(dashboard): one-line note for active members awaiting Slack invite

Renders only when status==='active' && !slackInvited. Hidden for
pending_payment, suspended, cancelled, guest, and any member already
flagged as invited. Lives inside the existing ClientOnly tree at the
top of the dashboard so it never SSRs.

Plain inline text in the welcome region — no banner, no callout. The
2–3 week window is admin-side workflow; the copy avoids cohort/wave
language.

app/pages/member/dashboard.vue

@@ -38,6 +38,10 @@
               <CircleBadge :circle="memberData?.circle || 'community'" />
               <span>${{ memberData?.contributionAmount ?? 0 }} CAD/mo</span>
             </div>
+            <p v-if="showSlackComingNote" class="slack-coming-note">
+              Slack workspace access is part of your membership. Your invitation
+              typically arrives within 2&ndash;3 weeks of joining.
+            </p>
           </PageHeader>
 
           <!-- Upcoming Events + Quick Actions -->
@@ -224,6 +228,10 @@ const { isActive, statusConfig, isPendingPayment, canPeerSupport } =
 
 const route = useRoute();
 const isNewSignup = computed(() => route.query.welcome === "1");
+const showSlackComingNote = computed(
+  () =>
+    memberData.value?.status === "active" && !memberData.value?.slackInvited,
+);
 const welcomeTitle = computed(() => {
   const name = memberData.value?.name || "";
   return isNewSignup.value
@@ -468,6 +476,13 @@ useHead({
   margin-top: 8px;
 }
 
+.slack-coming-note {
+  margin-top: 12px;
+  font-size: 12px;
+  color: var(--text-dim);
+  line-height: 1.65;
+}
+
 .content-row {
   display: grid;
   grid-template-columns: repeat(2, minmax(0, 1fr));