Label night-session products and hide day-only symbols at night.

Mark tradable varieties with a night tag; during 21:00-02:30 filter out index futures and other products without night sessions from symbol picker and recommend list.

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

install_trading.py

@@ -17,7 +17,7 @@ from flask import flash, jsonify, redirect, render_template, request, url_for, R
 from contract_specs import calc_position_metrics, get_contract_spec
 from fee_specs import calc_fee_breakdown
 from kline_stream import sse_format
-from market_sessions import is_trading_session
+from market_sessions import is_night_trading_session, is_trading_session
 from position_sizing import (
     MODE_AMOUNT,
     MODE_FIXED,
@@ -1493,6 +1493,7 @@ def install_trading(app, *, login_required, require_nav, get_db, get_setting, se
             "trading_mode_label": trading_mode_label(get_setting),
             "risk_status": risk,
             "trading_session": is_trading_session(),
+            "night_session": is_night_trading_session(),
             "pending_order_timeout_min": get_pending_order_timeout_min(get_setting),
             "sync_state": trading_state.sync_state,
             "sync_label": trading_state.sync_label(),
@@ -1636,6 +1637,7 @@ def install_trading(app, *, login_required, require_nav, get_db, get_setting, se
                 ctp_auto_connect=is_ctp_auto_connect_enabled(get_setting),
                 recommend_rows=rec_cache.get("rows") or [],
                 recommend_updated_at=rec_cache.get("updated_at"),
+                night_session=is_night_trading_session(),
                 product_categories=PRODUCT_CATEGORIES,
             )
         finally: