docs: add English quick reference to help

templates/user_manual.html

@@ -17,6 +17,9 @@
     .help-nav a { color: #fff; border: 1px solid rgba(255,255,255,0.58); border-radius: 5px; padding: 7px 13px; text-decoration: none; font-size: 13px; font-weight: 700; background: rgba(255,255,255,0.08); }
     .help-nav a:hover { background: rgba(255,255,255,0.18); }
     .manual-shell { max-width: 1180px; margin: 28px auto; padding: 0 16px 60px; }
+    .document-actions { display: flex; gap: 10px; flex-wrap: wrap; margin: 0 0 18px; }
+    .document-actions a { display: inline-block; color: #1F5438; border: 1px solid #cddbd4; border-radius: 6px; background: #fff; padding: 8px 12px; text-decoration: none; font-size: 13px; font-weight: 700; box-shadow: 0 1px 6px rgba(0,0,0,0.04); }
+    .document-actions a:hover { background: #eef4f1; }
     .manual-layout { display: grid; grid-template-columns: 260px minmax(0, 1fr); gap: 24px; align-items: start; }
     .manual-toc { position: sticky; top: 18px; background: #fff; border: 1px solid #dfe7e2; border-radius: 8px; padding: 16px; box-shadow: 0 2px 12px rgba(0,0,0,0.05); max-height: calc(100vh - 36px); overflow: auto; }
     .manual-toc h2 { color: #1F5438; font-size: 14px; margin-bottom: 12px; text-transform: uppercase; letter-spacing: 0; }
@@ -68,11 +71,21 @@
       <nav class="help-nav" aria-label="Help navigation">
         <a href="{{ url_for('index') }}">Calculator</a>
         <a href="{{ url_for('help_index') }}">Help</a>
+        <a href="{{ url_for('user_manual') }}">User Manual</a>
+        <a href="{{ url_for('quick_reference') }}">Quick Reference</a>
+        <a href="{{ url_for('recent_changes') }}">Recent Changes</a>
       </nav>
     </div>
   </header>
 
   <main class="manual-shell">
+    {% if document_actions %}
+      <nav class="document-actions" aria-label="Related documents">
+        {% for action in document_actions %}
+          <a href="{{ action.href }}">{{ action.label }}</a>
+        {% endfor %}
+      </nav>
+    {% endif %}
     {% if render_error %}
       <section class="manual-error" role="alert">
         <strong>{{ error_title }}</strong>