Aggiunge annunci in-app/sito, contatti e migliora UI copertina sul portale.

Include admin/API/banner nativi, form contatti e reset copertina standard con layout edit più ampio.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/views/contact_mailer/inquiry.html.erb

@@ -0,0 +1,13 @@
+<p><strong><%= t("mailers.contact.heading") %></strong></p>
+
+<p>
+  <%= t("mailers.contact.name") %> <%= @name %><br>
+  <%= t("mailers.contact.email") %> <%= @email %><br>
+  <%= t("mailers.contact.club") %> <%= @club_name.presence || t("mailers.contact.club_none") %><br>
+  <%= t("mailers.contact.topic") %> <%= t("mailers.contact.topic_labels.#{@topic}") %>
+</p>
+
+<p><%= t("mailers.contact.message") %></p>
+<p style="white-space:pre-wrap"><%= @message %></p>
+
+<p style="color:#666;font-size:12px"><%= t("mailers.contact.footer") %></p>