Add event/organisation location with Google Maps links

Events and the organisation profile now have an address, with a
"Directions" link and an embedded Google Maps view (no API key
required) shown on event pages, event cards, and the Contact page.
New events default their location to the org's configured address.

frontend/src/app/contact/page.tsx

@@ -5,6 +5,7 @@ import { Navbar } from "@/components/layout/Navbar";
 import { Footer } from "@/components/layout/Footer";
 import { useSiteSettings } from "@/contexts/SiteSettingsContext";
 import { appName } from "@/lib/siteConfig";
+import { LocationMap } from "@/components/events/LocationMap";
 
 export default function ContactPage() {
   const { settings, loading } = useSiteSettings();
@@ -68,6 +69,12 @@ export default function ContactPage() {
             </div>
           )}
         </div>
+
+        {address && (
+          <div className="mt-8 border rounded-xl p-5 bg-white shadow-sm">
+            <LocationMap address={address} />
+          </div>
+        )}
       </main>
       <Footer />
     </div>