feat: 币种输入旁实时显示交易所现价

Shared SymbolLivePrice polls /api/order_defaults on input with debounce; wired to trade, key monitor, trend, and key focus forms.

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

lib/instance/templates/embed_shell.html

@@ -7,7 +7,7 @@
     <link rel="stylesheet" href="/static/instance_theme_early.css?v=4">
     <link rel="stylesheet" href="/static/account_risk_badge.css?v=4">
     <link rel="stylesheet" href="/static/instance_page.css?v=2">
-    <link rel="stylesheet" href="/static/instance_theme.css?v=49">
+    <link rel="stylesheet" href="/static/instance_theme.css?v=50">
     <script src="/static/account_risk_badge.js?v=4"></script>
     <meta name="theme-color" content="#0b0d14">
     <title>{{ exchange_display }} · 加密货币 | 交易监控复盘系统</title>
@@ -121,6 +121,7 @@
 <script src="/static/ai_review_render.js?v=2"></script>
 <script src="/static/form_submit_guard.js?v=2"></script>
 <script src="/static/manual_order_rr_preview.js?v=5"></script>
+<script src="/static/symbol_live_price.js?v=1"></script>
 <script src="/static/strategy_roll.js?v=6"></script>
 <script src="/static/key_monitor_form.js?v=2"></script>
 {% include 'embed_boot_scripts.html' %}