fix(i18n): convert remaining $t() to server-side _() and fix store dashboard language

- Convert storefront enrollment $t() calls to server-side _() to silence
  dev-toolbar warnings (welcome bonus + join button)
- Fix store base template I18n.init() to use current_language (from middleware)
  instead of dashboard_language (hardcoded store config) so language changes
  take effect immediately
- Switch admin loyalty routes to use get_admin_context() for proper i18n support
- Switch store loyalty routes to use core get_store_context() from page_context
- Pass program object to storefront enrollment context for server-side rendering
- Add LANG-011 architecture rule: enforce $t()/_() over I18n.t() in templates
- Fix duplicate file_pattern key in LANG-004 rule (YAML validation error)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/modules/loyalty/templates/loyalty/storefront/enroll.html

@@ -16,7 +16,7 @@
             <img src="{{ store.logo_url }}" alt="{{ store.name }}" class="h-16 w-auto mx-auto mb-4">
             {% endif %}
             <h1 class="text-3xl font-bold text-gray-900 dark:text-white">{{ _('loyalty.enrollment.title') }}</h1>
-            <p class="mt-2 text-gray-600 dark:text-gray-400" x-text="I18n.t('loyalty.enrollment.subtitle', {points: program?.points_per_euro || 1})"></p>
+            <p class="mt-2 text-gray-600 dark:text-gray-400">{{ _('loyalty.enrollment.subtitle', points=program.points_per_euro if program else 1) }}</p>
         </div>
 
         <!-- Loading -->
@@ -38,7 +38,7 @@
                  class="p-4 text-center text-white"
                  :style="'background-color: ' + (program?.card_color || 'var(--color-primary)')">
                 <span x-html="$icon('gift', 'w-6 h-6 inline mr-2')"></span>
-                <span class="font-semibold" x-text="I18n.t('loyalty.enrollment.welcome_bonus', {points: program?.welcome_bonus_points})"></span>
+                <span class="font-semibold">{{ _('loyalty.enrollment.welcome_bonus', points=program.welcome_bonus_points if program else 0) }}</span>
             </div>
 
             <form @submit.prevent="submitEnrollment" class="p-6 space-y-4">
@@ -119,7 +119,7 @@
                         class="w-full py-3 px-4 text-white font-semibold rounded-lg transition-colors disabled:opacity-50"
                         :style="'background-color: ' + (program?.card_color || 'var(--color-primary)')">
                     <span x-show="enrolling" x-html="$icon('spinner', 'w-5 h-5 inline animate-spin mr-2')"></span>
-                    <span x-text="enrolling ? I18n.t('loyalty.enrollment.form.joining') : I18n.t('loyalty.enrollment.form.join_button', {points: program?.welcome_bonus_points || 0})"></span>
+                    <span x-text="enrolling ? '{{ _('loyalty.enrollment.form.joining') }}' : '{{ _('loyalty.enrollment.form.join_button', points=program.welcome_bonus_points if program else 0) }}'"></span>
                 </button>
             </form>