Force French locale on master and rebrand header tag

- keycloak-init now enables i18n on master with French as the only
  supported locale and the default, so all login pages render in fr.
- Replace dynamic realm.displayName tag (which showed 'Keycloak') with
  hardcoded '// Connexion sécurisée' in the theme header.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docker-compose.yml

@@ -83,7 +83,10 @@ services:
           -s "smtpServer.ssl=false" \
           -s "smtpServer.user=$$SMTP_USER" \
           -s "smtpServer.password=$$SMTP_PASSWORD" \
-          -s "loginTheme=$$LOGIN_THEME"
+          -s "loginTheme=$$LOGIN_THEME" \
+          -s "internationalizationEnabled=true" \
+          -s 'supportedLocales=["fr"]' \
+          -s "defaultLocale=fr"
         echo "Master realm configured."
     networks:
       - keycloak-net

themes/ecosplay/login/template.ftl

@@ -53,7 +53,7 @@
 
                 <!-- Header -->
                 <div class="mb-8 pb-6 border-b-4 border-gray-900">
-                    <p class="text-indigo-600 font-black uppercase tracking-[0.3em] mb-3 text-xs">// ${realm.displayName!"E-Cosplay"}</p>
+                    <p class="text-indigo-600 font-black uppercase tracking-[0.3em] mb-3 text-xs">// Connexion sécurisée</p>
                     <h1 class="text-4xl md:text-5xl font-black uppercase tracking-tighter leading-[0.9]">
                         <#nested "header">
                     </h1>