增加数据同步功能，支持从 akshare 拉取合约日线并自动计算振幅

ft-app/app/templates/admin.html

@@ -5,6 +5,17 @@
 
 {% block content %}
 
+
+{# ── Sync Bar ── #}
+<div style="display:flex;align-items:center;gap:12px;margin-bottom:20px;padding:14px 18px;background:var(--surface);border:1px solid var(--border);border-radius:10px;">
+  <span style="font-size:0.85rem;color:var(--sub);">数据同步</span>
+  <form method="post" action="/admin/sync" style="display:inline;">
+    <button type="submit" class="btn btn-primary" style="font-size:0.82rem;padding:6px 16px;">同步全部合约</button>
+  </form>
+  {% if request.query_params.get('synced') %}
+  <span style="font-size:0.82rem;color:var(--success-fg);">✓ 已同步 {{ request.query_params.synced }} 条</span>
+  {% endif %}
+</div>
 {# ── New Product ── #}
 <div class="section-title">新建品种</div>
 <div class="form-card" style="margin-bottom:24px;">
@@ -65,7 +76,12 @@
       <span class="badge badge-down">停用</span>
       {% endif %}
     </td>
-    <td><a href="/contracts/{{ c.code }}" style="color:var(--accent);text-decoration:none;">查看 →</a></td>
+    <td>
+      <a href="/contracts/{{ c.code }}" style="color:var(--accent);text-decoration:none;">查看</a>
+      <form method="post" action="/admin/sync/{{ c.code }}" style="display:inline;margin-left:8px;">
+        <button style="background:none;border:none;color:var(--accent);cursor:pointer;font-size:0.78rem;">↻ 同步</button>
+      </form>
+    </td>
     <td>
       <form method="post" action="/admin/contract/{{ c.id }}/toggle" style="display:inline;">
         <button style="background:none;border:none;color:var(--sub);cursor:pointer;font-size:0.82rem;">