品牌化重构: StreamCore + 现代UI主题 + 英文界面

- 移除所有emoji (HomePage中的🎬改为VideoCameraOutlined图标)
- 主题重设计: 深蓝色系主色(#1E3A5F),系统sans-serif字体
  白色/浅灰背景,现代卡片阴影和圆角,完全去除复古感
- 首页移除管理入口,纯观众视角(渐变横幅+卡片列表)
- 统一品牌名称 StreamCore (替换LiveStream)
- 全部界面英文(antd默认locale,去除zhCN)
- 登录页渐变+卡片居中布局

frontend/src/admin/pages/Settings.tsx

@@ -7,9 +7,9 @@ import api from '../../api/client'
 const { Title } = Typography
 
 const strategies = [
-  { value: 'round-robin', label: '轮询 (Round-Robin)' },
-  { value: 'weighted', label: '权重 (Weighted)' },
-  { value: 'least-conn', label: '最少连接 (Least Connections)' },
+  { value: 'round-robin', label: 'Round-Robin' },
+  { value: 'weighted', label: 'Weighted' },
+  { value: 'least-conn', label: 'Least Connections' },
 ]
 
 export default function SettingsPage() {
@@ -36,8 +36,8 @@ export default function SettingsPage() {
     try {
       await api.put('/nodes/strategy', { strategy: val, multicast_enabled: multicastEnabled })
       setStrategy(val)
-      message.success('策略已更新')
-    } catch { message.error('更新失败') }
+      message.success('Strategy updated')
+    } catch { message.error('Update failed') }
     setSaving(false)
   }
 
@@ -45,17 +45,17 @@ export default function SettingsPage() {
     setMulticastEnabled(val)
     try {
       await api.put('/nodes/strategy', { strategy, multicast_enabled: val })
-      message.success('组播设置已更新')
-    } catch { message.error('更新失败') }
+      message.success('Multicast settings updated')
+    } catch { message.error('Update failed') }
   }
 
   return (
     <div style={{ maxWidth: 720 }}>
-      <Title level={3} style={{ marginBottom: 24 }}>系统设置</Title>
+      <Title level={3} style={{ marginBottom: 24, fontWeight: 600 }}>System Settings</Title>
 
-      <Card title="负载均衡" style={{ marginBottom: 24 }}>
-        <Descriptions column={1} labelStyle={{ width: 140 }}>
-          <Descriptions.Item label="均衡策略">
+      <Card title="Load Balancing" style={{ marginBottom: 24, borderRadius: 12 }}>
+        <Descriptions column={1} labelStyle={{ width: 120 }}>
+          <Descriptions.Item label="Strategy">
             <Select
               value={strategy}
               onChange={saveStrategy}
@@ -67,14 +67,14 @@ export default function SettingsPage() {
         </Descriptions>
       </Card>
 
-      <Card title="组播设置">
-        <Descriptions column={1} labelStyle={{ width: 140 }}>
-          <Descriptions.Item label="启用组播">
+      <Card title="Multicast" style={{ borderRadius: 12 }}>
+        <Descriptions column={1} labelStyle={{ width: 120 }}>
+          <Descriptions.Item label="Enable">
             <Switch checked={multicastEnabled} onChange={toggleMulticast} />
           </Descriptions.Item>
-          <Descriptions.Item label="网络状态">
-            <span style={{ color: multicastAvailable ? '#52c41a' : '#999' }}>
-              {multicastAvailable ? '可用 — 优先使用组播分发' : '不可用 — 回退至单播'}
+          <Descriptions.Item label="Network Status">
+            <span style={{ color: multicastAvailable ? '#2E7D32' : '#999' }}>
+              {multicastAvailable ? 'Available - using multicast' : 'Unavailable - fallback to unicast'}
             </span>
           </Descriptions.Item>
         </Descriptions>