Merge upstream/main into pr/upstream-model-tracking

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

frontend/src/i18n/locales/en.ts

@@ -1508,6 +1508,8 @@ export default {
         rateMultiplier: 'Rate Multiplier',
         type: 'Type',
         accounts: 'Accounts',
+        capacity: 'Capacity',
+        usage: 'Usage',
         status: 'Status',
         actions: 'Actions',
         billingType: 'Billing Type',
@@ -1516,6 +1518,12 @@ export default {
         userNotes: 'Notes',
         userStatus: 'Status'
       },
+      usageToday: 'Today',
+      usageTotal: 'Total',
+      accountsAvailable: 'Avail:',
+      accountsRateLimited: 'Limited:',
+      accountsTotal: 'Total:',
+      accountsUnit: '',
       rateAndAccounts: '{rate}x rate · {count} accounts',
       accountsCount: '{count} accounts',
       form: {
@@ -1697,6 +1705,7 @@ export default {
       revokeSubscription: 'Revoke Subscription',
       allStatus: 'All Status',
       allGroups: 'All Groups',
+      allPlatforms: 'All Platforms',
       daily: 'Daily',
       weekly: 'Weekly',
       monthly: 'Monthly',
@@ -1762,7 +1771,37 @@ export default {
       pleaseSelectGroup: 'Please select a group',
       validityDaysRequired: 'Please enter a valid number of days (at least 1)',
       revokeConfirm:
-        "Are you sure you want to revoke the subscription for '{user}'? This action cannot be undone."
+        "Are you sure you want to revoke the subscription for '{user}'? This action cannot be undone.",
+      guide: {
+        title: 'Subscription Management Guide',
+        subtitle: 'Subscription mode lets you assign time-based usage quotas to users, with daily/weekly/monthly limits. Follow these steps to get started.',
+        showGuide: 'Usage Guide',
+        step1: {
+          title: 'Create a Subscription Group',
+          line1: 'Go to "Group Management" page, click "Create Group"',
+          line2: 'Set billing type to "Subscription", configure daily/weekly/monthly quota limits',
+          line3: 'Save the group and ensure its status is "Active"',
+          link: 'Go to Group Management'
+        },
+        step2: {
+          title: 'Assign Subscription to User',
+          line1: 'Click the "Assign Subscription" button in the top right',
+          line2: 'Search for a user by email and select them',
+          line3: 'Choose a subscription group, set validity days, then click "Assign"'
+        },
+        step3: {
+          title: 'Manage Existing Subscriptions'
+        },
+        actions: {
+          adjust: 'Adjust',
+          adjustDesc: 'Extend or shorten the subscription validity period',
+          resetQuota: 'Reset Quota',
+          resetQuotaDesc: 'Reset daily/weekly/monthly usage to zero',
+          revoke: 'Revoke',
+          revokeDesc: 'Immediately terminate the subscription (irreversible)'
+        },
+        tip: 'Tip: Only groups with billing type "Subscription" and status "Active" appear in the group dropdown. If no options are available, create one in Group Management first.'
+      }
     },
 
     // Accounts

frontend/src/i18n/locales/zh.ts

@@ -1564,6 +1564,8 @@ export default {
         priority: '优先级',
         apiKeys: 'API 密钥数',
         accounts: '账号数',
+        capacity: '容量',
+        usage: '用量',
         status: '状态',
         actions: '操作',
         billingType: '计费类型',
@@ -1572,6 +1574,12 @@ export default {
         userNotes: '备注',
         userStatus: '状态'
       },
+      usageToday: '今日',
+      usageTotal: '累计',
+      accountsAvailable: '可用:',
+      accountsRateLimited: '限流:',
+      accountsTotal: '总量:',
+      accountsUnit: '个账号',
       form: {
         name: '名称',
         description: '描述',
@@ -1777,6 +1785,7 @@ export default {
       revokeSubscription: '撤销订阅',
       allStatus: '全部状态',
       allGroups: '全部分组',
+      allPlatforms: '全部平台',
       daily: '每日',
       weekly: '每周',
       monthly: '每月',
@@ -1841,7 +1850,37 @@ export default {
       pleaseSelectUser: '请选择用户',
       pleaseSelectGroup: '请选择分组',
       validityDaysRequired: '请输入有效的天数（至少1天）',
-      revokeConfirm: "确定要撤销 '{user}' 的订阅吗？此操作无法撤销。"
+      revokeConfirm: "确定要撤销 '{user}' 的订阅吗？此操作无法撤销。",
+      guide: {
+        title: '订阅管理教程',
+        subtitle: '订阅模式允许你按时间周期为用户分配使用额度，支持日/周/月配额限制。按照以下步骤即可完成配置。',
+        showGuide: '使用指南',
+        step1: {
+          title: '创建订阅分组',
+          line1: '前往「分组管理」页面，点击「创建分组」',
+          line2: '将计费类型设为「订阅」，配置日/周/月额度限制',
+          line3: '保存分组，确保状态为「正常」',
+          link: '前往分组管理'
+        },
+        step2: {
+          title: '分配订阅给用户',
+          line1: '点击本页右上角「分配订阅」按钮',
+          line2: '在弹窗中搜索用户邮箱并选择目标用户',
+          line3: '选择订阅分组、设置有效期天数，点击「分配」'
+        },
+        step3: {
+          title: '管理已有订阅'
+        },
+        actions: {
+          adjust: '调整',
+          adjustDesc: '延长或缩短订阅有效期',
+          resetQuota: '重置配额',
+          resetQuotaDesc: '将日/周/月用量归零，重新开始计算',
+          revoke: '撤销',
+          revokeDesc: '立即终止该用户的订阅，不可恢复'
+        },
+        tip: '提示：订阅分组下拉列表中只会显示计费类型为「订阅」且状态为「正常」的分组。如果没有可选项，请先到分组管理中创建。'
+      }
     },
 
     // Accounts Management