新增行情K线页，支持分时与多周期图表

扩展新浪K线拉取与合成逻辑，提供 ECharts 交互图表及实时报价 API。

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

templates/base.html

@@ -454,6 +454,7 @@
                 <a href="{{ url_for('plans') }}" class="{% if request.endpoint == 'plans' %}active{% endif %}">开单计划</a>
                 <a href="{{ url_for('keys') }}" class="{% if request.endpoint == 'keys' %}active{% endif %}">关键位监控</a>
                 <a href="{{ url_for('positions') }}" class="{% if request.endpoint == 'positions' %}active{% endif %}">持仓监控</a>
+                <a href="{{ url_for('market_page') }}" class="{% if request.endpoint == 'market_page' %}active{% endif %}">行情K线</a>
                 <a href="{{ url_for('records') }}" class="{% if request.endpoint in ('records', 'trades') %}active{% endif %}">交易记录与复盘</a>
                 <a href="{{ url_for('stats') }}" class="{% if request.endpoint == 'stats' %}active{% endif %}">统计分析</a>
                 <a href="{{ url_for('fees') }}" class="{% if request.endpoint == 'fees' %}active{% endif %}">手续费配置</a>