feat: implement CSRF protection across forms and routes

crates/adapters/template-askama/templates/diary.html

@@ -30,6 +30,7 @@
       {% if let Some(uid) = ctx.user_id %}
         {% if *uid == entry.review().user_id().value() %}
         <form method="post" action="/reviews/{{ entry.review().id().value() }}/delete" class="delete-form">
+          <input type="hidden" name="_csrf" value="{{ ctx.csrf_token }}">
           <button type="submit">Delete</button>
         </form>
         {% endif %}