fix(templates): fix unhashable dict in Jinja2 cache by converting available_languages global to function

app/templates/base.html

@@ -23,7 +23,7 @@
             <div class="lang-switcher" id="langSwitcher">
                 <button type="button" class="lang-globe" onclick="document.getElementById('langDropdown').classList.toggle('show')">🌐</button>
                 <div class="lang-dropdown" id="langDropdown">
-                    {% for code, name in available_languages.items() %}
+                    {% for code, name in get_languages().items() %}
                     <form method="post" action="/settings/language">
                         <input type="hidden" name="language" value="{{ code }}">
                         <button type="submit" class="lang-option {% if user.language == code %}active{% endif %}">{{ name }}</button>