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/PrivacyToggle.vue

@@ -1,66 +1,44 @@
 <template>
-  <div class="priv segmented">
-    <span
-      v-for="opt in options"
-      :key="opt.value"
-      :class="{ on: modelValue === opt.value }"
-      @click="$emit('update:modelValue', opt.value)"
-      >{{ opt.label }}</span
-    >
-  </div>
+  <label class="priv">
+    <USwitch
+      :model-value="isPrivate"
+      aria-label="Private"
+      size="xs"
+      @update:model-value="onChange"
+    />
+    <span class="priv-label">Private</span>
+  </label>
 </template>
 
 <script setup>
-defineProps({
-  modelValue: { type: String, default: "public" },
+const props = defineProps({
+  modelValue: { type: String, default: "members" },
 });
 
-defineEmits(["update:modelValue"]);
+const emit = defineEmits(["update:modelValue"]);
 
-const options = [
-  { label: "Public", value: "public" },
-  { label: "Members", value: "members" },
-  { label: "Private", value: "private" },
-];
+// Treat legacy "public" values as "members" (visible to signed-in members).
+const isPrivate = computed(() => props.modelValue === "private");
+
+const onChange = (val) => {
+  emit("update:modelValue", val ? "private" : "members");
+};
 </script>
 
 <style scoped>
 .priv {
   display: inline-flex;
-  gap: 0;
-  font-size: 9px;
-  font-family: "Commit Mono", monospace;
-  letter-spacing: 0.02em;
-}
-
-.priv span {
-  padding: 2px 7px;
-  height: 18px;
-  display: flex;
   align-items: center;
-  justify-content: center;
-  border: 1px dashed var(--border);
+  gap: 6px;
+  font-size: 10px;
+  font-family: "Commit Mono", monospace;
+  letter-spacing: 0.04em;
   color: var(--text-faint);
-  cursor: pointer;
-  transition: all 0.12s;
   user-select: none;
-  white-space: nowrap;
-  position: relative;
+  cursor: pointer;
 }
 
-.priv span + span {
-  margin-left: -1px;
-}
-
-.priv span:hover {
-  color: var(--text-dim);
-}
-
-.priv span.on {
-  background: var(--surface);
-  color: var(--text-bright);
-  border-color: var(--candle);
-  border-style: solid;
-  z-index: 1;
+.priv-label {
+  line-height: 1;
 }
 </style>