feat: 消息推送自定义模板与独立设置页

后端:
- 新增通知模板表与实体、DTO、Repository、NotificationTemplateService
- 支持 {{variable}} 模板语法，提供模板类型与变量接口
- TelegramNotificationService 改为通过模板渲染发送（ORDER_SUCCESS/ORDER_FAILED/ORDER_FILTERED/CRYPTO_TAIL_SUCCESS/REDEEM_SUCCESS/REDEEM_NO_RETURN）
- 模板 CRUD、重置默认、测试发送接口
- 补全订单过滤相关 i18n key（zh/en/zh-TW）

前端:
- 消息推送设置抽离为独立页 /system-settings/notification
- 系统设置概览改为入口卡片，侧栏增加「消息推送设置」菜单
- NotificationSettingsPage: 机器人配置 + 模板配置双卡片布局（与概览一致）
- 模板配置支持选择类型、编辑内容、变量面板（点击复制、悬停说明）、保存/重置/测试
- 多语言 key 补全（notificationSettings.templates.*、templateTypes.*）

Made-with: Cursor

backend/src/main/resources/i18n/messages_en.properties

@@ -17,6 +17,14 @@ notification.order.available_balance=Available Balance
 notification.order.error_info=Error Information
 notification.order.unknown_account=Unknown Account
 notification.order.calculate_failed=Calculation Failed
+notification.order.filtered=Order Filtered
+notification.order.filter_reason=Filter Reason
+notification.order.filter_type=Filter Type
+notification.filter.type.order_depth=Insufficient Order Depth
+notification.filter.type.spread=Spread Too Large
+notification.filter.type.orderbook_depth=Insufficient Orderbook Depth
+notification.filter.type.price_validity=Invalid Price
+notification.filter.type.market_status=Market Not Tradable
 notification.tail.order.success=Crypto spread strategy order success
 notification.tail.strategy=Strategy
 notification.redeem.success=Position Redeemed Successfully

backend/src/main/resources/i18n/messages_zh_CN.properties

@@ -17,6 +17,14 @@ notification.order.available_balance=可用余额
 notification.order.error_info=错误信息
 notification.order.unknown_account=未知账户
 notification.order.calculate_failed=计算失败
+notification.order.filtered=订单被过滤
+notification.order.filter_reason=过滤原因
+notification.order.filter_type=过滤类型
+notification.filter.type.order_depth=订单深度不足
+notification.filter.type.spread=价差过大
+notification.filter.type.orderbook_depth=订单簿深度不足
+notification.filter.type.price_validity=价格不合理
+notification.filter.type.market_status=市场状态不可交易
 notification.tail.order.success=加密价差策略下单成功
 notification.tail.strategy=策略
 notification.redeem.success=仓位赎回成功

backend/src/main/resources/i18n/messages_zh_TW.properties

@@ -17,6 +17,14 @@ notification.order.available_balance=可用餘額
 notification.order.error_info=錯誤信息
 notification.order.unknown_account=未知賬戶
 notification.order.calculate_failed=計算失敗
+notification.order.filtered=訂單被過濾
+notification.order.filter_reason=過濾原因
+notification.order.filter_type=過濾類型
+notification.filter.type.order_depth=訂單深度不足
+notification.filter.type.spread=價差過大
+notification.filter.type.orderbook_depth=訂單簿深度不足
+notification.filter.type.price_validity=價格不合理
+notification.filter.type.market_status=市場狀態不可交易
 notification.tail.order.success=加密價差策略下單成功
 notification.tail.strategy=策略
 notification.redeem.success=倉位贖回成功