feat: organizers, meetups UI, Plausible analytics, and migration tooling

- Add organizer model/API, admin and public organizer pages, meetup cards
- Refresh events/home/contact; add calendar dialog and carousel components
- Optional Plausible via NEXT_PUBLIC_PLAUSIBLE_* env vars in root layout
- Prisma migration, seed updates, baseline-and-migrate script

Made-with: Cursor

frontend/app/admin/overview/page.tsx

@@ -4,7 +4,7 @@ import { useEffect, useState } from "react";
 import { useRouter } from "next/navigation";
 import { useAuth } from "@/hooks/useAuth";
 import { api } from "@/lib/api";
-import { getMeetupStartUtc } from "@/lib/meetupEventTime";
+import { formatMeetupCivilDateLong, getMeetupStartUtc } from "@/lib/meetupEventTime";
 import { formatDate } from "@/lib/utils";
 import { Calendar, FileText, Tag, User, Plus, Download, FolderOpen } from "lucide-react";
 import Link from "next/link";
@@ -94,7 +94,7 @@ export default function OverviewPage() {
           <h2 className="text-lg font-semibold text-on-surface mb-3">Next Upcoming Meetup</h2>
           <p className="text-primary font-semibold">{upcomingMeetup.title}</p>
           <p className="text-on-surface/60 text-sm mt-1">
-            {formatDate(upcomingMeetup.date)} · {upcomingMeetup.location}
+            {formatMeetupCivilDateLong(upcomingMeetup.date)} · {upcomingMeetup.location}
           </p>
         </div>
       )}