本地手续费配置（标准×2），持仓/交易记录/复盘/统计展示扣费后盈亏

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

templates/base.html

@@ -341,7 +341,7 @@
         .pos-card-head .title{font-size:1rem;font-weight:600;color:var(--text-title)}
         .pos-card-meta{font-size:.75rem;color:var(--text-muted);margin-bottom:.65rem}
         .pos-card-meta strong{color:var(--text-primary)}
-        .pos-metrics{display:grid;grid-template-columns:repeat(3,1fr);gap:.5rem .65rem;margin-bottom:.65rem}
+        .pos-metrics{display:grid;grid-template-columns:repeat(4,1fr);gap:.5rem .65rem;margin-bottom:.65rem}
         .pos-metrics .cell label{display:block;font-size:.68rem;color:var(--text-muted);margin-bottom:.15rem}
         .pos-metrics .cell div{font-size:.88rem;color:var(--text-primary)}
         .pos-metrics .cell.pnl-pos div{color:var(--profit)}
@@ -405,6 +405,7 @@
                 <a href="{{ url_for('positions') }}" class="{% if request.endpoint == 'positions' %}active{% endif %}">持仓监控</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>
                 <a href="{{ url_for('settings') }}" class="{% if request.endpoint == 'settings' %}active{% endif %}">系统设置</a>
             </nav>
         </header>