feat(events): pipe displayTimezone through list and sidebar formatters

Sidebar (EventsMiniSidebar), public events list, member dashboard
"Upcoming" block, and EventTicketPurchase all formatted dates in
viewer-local TZ. Switch each formatter to accept the event (or an
eventTimezone prop) and pass it to Intl.DateTimeFormat so the
displayed wall-clock matches the event's intended zone.

app/components/EventTicketPurchase.vue

@@ -231,6 +231,10 @@ const props = defineProps({
     type: String,
     required: true,
   },
+  eventTimezone: {
+    type: String,
+    default: "America/Toronto",
+  },
   userEmail: {
     type: String,
     default: null,
@@ -415,6 +419,7 @@ const formatEventDate = (date) => {
     month: "long",
     day: "numeric",
     year: "numeric",
+    timeZone: props.eventTimezone || "America/Toronto",
   });
 };
 </script>

app/components/EventsMiniSidebar.vue

@@ -6,7 +6,7 @@
     <div v-if="events?.length" class="em-rows">
       <div v-for="event in events" :key="event._id" class="em-item">
         <div class="em-inset em-item-body">
-          <span class="em-date">{{ formatDate(event.startDate) }}</span>
+          <span class="em-date">{{ formatDate(event) }}</span>
           <NuxtLink
             :to="`/events/${event.slug || event._id}`"
             class="em-title"
@@ -37,10 +37,13 @@ defineProps({
   events: { type: Array, default: () => [] },
 });
 
-const formatDate = (dateStr) => {
-  if (!dateStr) return "";
-  const d = new Date(dateStr);
-  return d.toLocaleDateString("en-US", { month: "short", day: "numeric" });
+const formatDate = (event) => {
+  if (!event?.startDate) return "";
+  return new Date(event.startDate).toLocaleDateString("en-US", {
+    month: "short",
+    day: "numeric",
+    timeZone: event.displayTimezone || "America/Toronto",
+  });
 };
 </script>