Add CSRF token handling to HTMX requests:

- Configure HTMX to include CSRF token in request headers
- Add global HTMX configuration in dashboard.html
- Fix CSRF token missing error in moderation actions

templates/moderation/dashboard.html

@@ -185,6 +185,11 @@
 
 {% block extra_js %}
 <script>
+// Configure HTMX to include CSRF token in all requests
+document.body.addEventListener('htmx:configRequest', function(evt) {
+    evt.detail.headers['X-CSRFToken'] = '{{ csrf_token }}';
+});
+
 document.body.addEventListener('htmx:beforeSwap', function(evt) {
     if (evt.detail.target.id === 'submissions-content') {
         evt.detail.shouldSwap = true;