feat: 导航开关与 CTP 柜台手续费

系统设置可开关五类导航；手续费默认从 CTP 查询同步，本地/AKShare 作离线兜底；补充 FEES.md。

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

install_trading.py

@@ -54,8 +54,9 @@ from vnpy_bridge import (
 )
 
 
-def install_trading(app, *, login_required, get_db, get_setting, set_setting, fetch_price, send_wechat_msg):
+def install_trading(app, *, login_required, require_nav, get_db, get_setting, set_setting, fetch_price, send_wechat_msg):
     """注册交易相关路由。"""
+    _nav = require_nav
 
     def _settings_dict() -> dict:
         return {
@@ -291,6 +292,7 @@ def install_trading(app, *, login_required, get_db, get_setting, set_setting, fe
 
     @app.route("/strategy")
     @login_required
+    @_nav("strategy")
     def strategy_page():
         conn = get_db()
         init_strategy_tables(conn)