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_page_fragment.html

@@ -65,7 +65,9 @@
                 <label style="display:flex;align-items:center;gap:4px;font-size:.82rem;color:#cfd3ef">
                     <input type="checkbox" name="order_chart" value="true"> 开仓后生成多周期K线图（各周期100根，含开平仓标记）
                 </label>
-                <span style="display:flex;align-items:center;padding:0 10px;font-size:.8rem;color:#8fc8ff">成交价自动取交易所实时+成交回报</span>
+                {% from 'symbol_live_price_snippet.html' import symbol_live_price_hint %}
+                {{ symbol_live_price_hint('order-symbol-live-price', 'order-symbol', 'order-direction') }}
+                <span class="symbol-live-price-note">下单成交价以交易所成交回报为准</span>
                 <input id="order-sl" name="sl" step="any" placeholder="止损价格" required>
                 <input id="order-fixed-rr" name="fixed_rr" type="number" min="0.01" step="0.01" placeholder="盈亏比(默认1.5)" value="1.5" title="止盈距离=止损距离×盈亏比">
                 <span id="order-tp-preview" style="display:none;font-size:.8rem;color:#8fc8ff;align-self:center">预估止盈：—</span>