feat(member): account/profile polish + tier upgrade flow

- Timezone: curated USelectMenu dropdown (app/config/timezones.js), preserves unknown saved values
- Profile save now uses useToast() for success/error; remove inline save banner
- Nav onboarding dot nudged down 1px for optical alignment with lowercase text
- Onboarding: skip a suggestion with POST /api/onboarding/track {skip}; member.onboarding.skipped map; does not affect graduation
- CirclePicker takes :saved-value so 'Current' badge stays until save completes
- PrivacyToggle is binary (USwitch labeled Private); member schema enum reduced to ['members','private']; zod coerces legacy 'public'
- New /member/payment-setup page: HelcimPay $0 verify + update-contribution, wired from account.vue via requiresPaymentSetup redirect
- Helcim portal: NUXT_PUBLIC_HELCIM_PORTAL_URL env + account.vue 'Manage billing in Helcim' link
- Migration script: scripts/migrate-privacy-public-to-members.js

app/components/CirclePicker.vue

@@ -4,13 +4,16 @@
       v-for="circle in circles"
       :key="circle.value"
       class="circle-option"
-      :class="{ current: modelValue === circle.value }"
+      :class="{
+        selected: modelValue === circle.value,
+        current: savedValue === circle.value,
+      }"
       @click="$emit('update:modelValue', circle.value)"
     >
       <span class="circle-name">{{ circle.label }}</span>
       <span class="circle-desc">{{ circle.description }}</span>
       <span
-        v-if="modelValue === circle.value"
+        v-if="savedValue === circle.value"
         class="circle-tag"
         :style="{ color: `var(--c-${circle.value})`, borderColor: `var(--c-${circle.value})` }"
       >Current</span>
@@ -21,6 +24,7 @@
 <script setup>
 defineProps({
   modelValue: { type: String, default: '' },
+  savedValue: { type: String, default: '' },
   circles: {
     type: Array,
     default: () => [
@@ -54,7 +58,7 @@ defineEmits(['update:modelValue'])
   background: var(--surface-hover);
 }
 
-.circle-option.current {
+.circle-option.selected {
   border-color: var(--candle);
   border-style: solid;
   background: var(--surface);
@@ -67,7 +71,7 @@ defineEmits(['update:modelValue'])
   margin-bottom: 4px;
 }
 
-.circle-option.current .circle-name {
+.circle-option.selected .circle-name {
   color: var(--candle);
 }