Completa i18n IT/EN/FR/DE/ES su sito pubblico, area autenticata e admin.

Tutte le view marketing, legali, viewer, dashboard e admin usano t(); mailer utente-facing e flash localizzati; admin con LocaleResolver e selettore lingua.

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

backend/app/views/admin/auth/new.html.erb

@@ -1,26 +1,26 @@
 <div style="max-width:360px;margin:4rem auto">
-  <h2>Accesso admin</h2>
+  <h2><%= t("admin.auth.new.title") %></h2>
   <% if flash[:alert] %>
     <p style="color:#ff6b6b"><%= flash[:alert] %></p>
   <% end %>
   <%= form_with url: admin_login_path, method: :post, local: true do %>
     <p>
-      <label for="username">Username</label><br>
+      <label for="username"><%= t("admin.auth.new.username_label") %></label><br>
       <input type="text" name="username" id="username" required autofocus autocomplete="username"
              style="width:100%;padding:0.5rem;margin-top:0.25rem;background:#1E1E1E;border:1px solid #333;color:#fff;border-radius:6px">
     </p>
     <p>
-      <label for="password">Password</label><br>
+      <label for="password"><%= t("admin.auth.new.password_label") %></label><br>
       <input type="password" name="password" id="password" required autocomplete="current-password"
              style="width:100%;padding:0.5rem;margin-top:0.25rem;background:#1E1E1E;border:1px solid #333;color:#fff;border-radius:6px">
     </p>
     <p>
       <button type="submit" style="background:#FF2D2D;color:#fff;border:0;padding:0.6rem 1.2rem;border-radius:6px;cursor:pointer;font-weight:700">
-        Accedi
+        <%= t("admin.auth.new.submit") %>
       </button>
     </p>
   <% end %>
   <p style="color:#888;font-size:0.85rem;margin-top:1.5rem">
-    Credenziali iniziali: <code>admin</code> / <code>admin</code>. Cambia la password dopo il primo accesso.
+    <%= t("admin.auth.new.initial_credentials_html") %>
   </p>
 </div>