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/contact/page.tsx

@@ -1,8 +1,7 @@
 import type { Metadata } from "next";
-import Link from "next/link";
 import { Navbar } from "@/components/public/Navbar";
 import { Footer } from "@/components/public/Footer";
-import { Send, Zap, ExternalLink } from "lucide-react";
+import { ContactChannelGrid } from "@/components/public/ContactChannelGrid";
 
 export const metadata: Metadata = {
   title: "Contact Us",
@@ -28,56 +27,7 @@ export default function ContactPage() {
             decentralized community — there is no central office or email inbox.
           </p>
 
-          <div className="grid grid-cols-1 sm:grid-cols-2 gap-6">
-            <a
-              href="https://t.me/belgianbitcoinembassy"
-              target="_blank"
-              rel="noopener noreferrer"
-              className="bg-surface-container-low p-8 rounded-xl hover:bg-surface-container transition-colors group"
-            >
-              <Send size={28} className="text-primary mb-4" />
-              <h2 className="text-xl font-bold mb-2">Telegram</h2>
-              <p className="text-on-surface-variant text-sm">
-                Join our Telegram group for quick questions and community chat.
-              </p>
-            </a>
-
-            <a
-              href="#"
-              className="bg-surface-container-low p-8 rounded-xl hover:bg-surface-container transition-colors group"
-            >
-              <Zap size={28} className="text-primary mb-4" />
-              <h2 className="text-xl font-bold mb-2">Nostr</h2>
-              <p className="text-on-surface-variant text-sm">
-                Follow us on Nostr for censorship-resistant communication.
-              </p>
-            </a>
-
-            <a
-              href="#"
-              className="bg-surface-container-low p-8 rounded-xl hover:bg-surface-container transition-colors group"
-            >
-              <ExternalLink size={28} className="text-primary mb-4" />
-              <h2 className="text-xl font-bold mb-2">X (Twitter)</h2>
-              <p className="text-on-surface-variant text-sm">
-                Follow us on X for announcements and updates.
-              </p>
-            </a>
-
-            <div className="bg-surface-container-low p-8 rounded-xl">
-              <h2 className="text-xl font-bold mb-2">Meetups</h2>
-              <p className="text-on-surface-variant text-sm mb-4">
-                The best way to connect is in person. Come to our monthly meetup
-                in Brussels.
-              </p>
-              <Link
-                href="/#meetup"
-                className="text-primary font-bold text-sm hover:underline"
-              >
-                See next meetup →
-              </Link>
-            </div>
-          </div>
+          <ContactChannelGrid />
         </div>
       </div>
       <Footer />