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/dashboard/layout.tsx

@@ -16,9 +16,6 @@ export default function DashboardLayout({ children }: { children: React.ReactNod
       router.push("/login");
       return;
     }
-    if (user.role === "ADMIN" || user.role === "MODERATOR") {
-      router.push("/admin/overview");
-    }
   }, [user, loading, router]);
 
   if (loading) {
@@ -33,7 +30,7 @@ export default function DashboardLayout({ children }: { children: React.ReactNod
     );
   }
 
-  if (!user || user.role === "ADMIN" || user.role === "MODERATOR") {
+  if (!user) {
     return null;
   }