fix(settings): push trading-hours changes to live user prices immediately

Recompute home price display on save, broadcast settings over SSE, and keep last-price status in sync without a user refresh.

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

database/sql/settings_menu_and_show_to_user.sql

@@ -123,6 +123,7 @@ UPDATE `settings` SET `show_to_user` = 1 WHERE `key` IN (
   'referral_show',
   'show_gold_ounce_price',
   'show_home_price_when_closed',
+  'show_last_price',
   'show_product_card_meta',
   'show_product_details',
   'show_product_trade_status',
@@ -137,6 +138,7 @@ UPDATE `settings` SET `show_to_user` = 1 WHERE `key` IN (
   'text_rule',
   'tracking_systems',
   'tracking_systems_enabled',
+  'trading_hours_by_day',
   'unit',
   'wss_enabled',
   'wss_path',