Rename positions nav to order monitor and set as default landing page.

Remove stats recalculate button; login and home now open /positions without affecting refresh on other routes.

Co-authored-by: Cursor <cursoragent@cursor.com>

templates/base.html

@@ -518,7 +518,7 @@
             <h1 class="site-title">国内期货 · 交易监控 + 复盘<span class="site-title-sub">FUTURES MONITOR SYSTEM</span></h1>
             <button type="button" class="nav-backdrop" id="nav-backdrop" aria-label="关闭菜单" hidden></button>
             <nav class="site-nav" id="site-nav">
-                <a href="{{ url_for('positions') }}" class="{% if request.endpoint in ('positions', 'trade_page', 'recommend_page') %}active{% endif %}">持仓监控</a>
+                <a href="{{ url_for('positions') }}" class="{% if request.endpoint in ('positions', 'trade_page', 'recommend_page') %}active{% endif %}">下单监控</a>
                 {% if nav_items.strategy %}<a href="{{ url_for('strategy_page') }}" class="{% if request.endpoint in ('strategy_page', 'strategy_records_page') %}active{% endif %}">策略交易</a>{% endif %}
                 {% if nav_items.plans %}<a href="{{ url_for('plans') }}" class="{% if request.endpoint == 'plans' %}active{% endif %}">开单计划</a>{% endif %}
                 <a href="{{ url_for('keys') }}" class="{% if request.endpoint == 'keys' %}active{% endif %}">关键位监控</a>