feat: add search and user data routes, services, and tests

app/templates/base.html

@@ -10,8 +10,11 @@
   <header class="site-header">
     <nav class="nav-bar">
       <a href="/" class="nav-brand">📚 HF Daily Papers</a>
+      <form class="nav-search" action="/search" method="get">
+        <input type="text" name="q" placeholder="搜索..." class="nav-search-input">
+      </form>
       <div class="nav-links">
-        <a href="/day/{{ today }}">今日</a>
+        <a href="/day/{{ today if today else '' }}">今日</a>
         <a href="/search">搜索</a>
         <a href="/reading-list">阅读列表</a>
       </div>
@@ -26,6 +29,7 @@
     <p>HF Daily Papers — 中文论文导览站 · 数据来源于 <a href="https://huggingface.co/papers" target="_blank">HuggingFace</a></p>
   </footer>
 
+  <script src="https://unpkg.com/htmx.org@2.0.4"></script>
   <script src="/static/js/app.js"></script>
   {% block scripts %}{% endblock %}
 </body>