GitLab

- Add IP restriction feature for API keys (whitelist/blacklist with CIDR support)
- Add IP address logging to usage logs (admin-only visibility)
- Remove billing_type column from usage logs UI (redundant)
- Use generic "Access denied" error message for security

Backend:
- New ip package with IP/CIDR validation and matching utilities
- Database migrations for ip_whitelist, ip_blacklist (api_keys) and ip_address (usage_logs)
- Middleware IP restriction check after API key validation
- Input validation for IP/CIDR patterns on create/update

Frontend:
- API key form with enable toggle for IP restriction
- Shield icon indicator in table for keys with IP restriction
- Removed billing_type filter and column from usage views

- Add user_agent field to UsageLog DTO and mapper
- Display User-Agent column in admin and user usage tables
- Add formatUserAgent helper to show friendly client names
- Include user_agent in Excel export
- Remove request_id column from admin usage table

问题修复:
- 恢复 Cost Tooltip 的成本分项明细 (input_cost, output_cost, cache 成本)
- 修复 Token Tooltip 双分隔线显示问题
- 修复 Tooltip 翻译键缺失问题，新增 costDetails/tokenDetails
- 恢复 Excel 导出格式化 (aoa_to_sheet + 翻译列头)

功能优化:
- 账号筛选从前端搜索改为后端搜索，避免一次加载 1000 条数据
- 行为与用户/API Key 筛选保持一致 (debounce + 后端分页)

后端改进：
- 新增 GetStatsWithFilters 方法支持完整筛选条件
- Stats 端点支持 account_id, group_id, model, stream, billing_type 参数
- 统一使用 filters 结构体，移除冗余的分支逻辑

前端改进：
- 统计卡片添加"所选范围内"文字提示
- 优化总消费显示格式，清晰展示实际费用和标准计费
- Token 和费用列添加问号图标 tooltip 显示详细信息
- API Key 搜索框体验优化：点击即显示下拉选项
- 选择用户后自动加载该用户的所有 API Key

- 扩展 Icon.vue 组件，新增 60+ 图标路径
  - 导航类: arrowRight, arrowLeft, arrowUp, arrowDown, chevronUp, externalLink
  - 状态类: checkCircle, xCircle, exclamationCircle, exclamationTriangle, infoCircle
  - 用户类: user, userCircle, userPlus, users
  - 文档类: document, clipboard, copy, inbox
  - 操作类: download, upload, filter, sort
  - 安全类: key, lock, shield
  - UI类: menu, calendar, home, terminal, gift, creditCard, mail
  - 数据类: chartBar, trendingUp, database, cube
  - 其他: bolt, sparkles, cloud, server, sun, moon, book 等

- 重构 56 个 Vue 组件，用 Icon 组件替换内联 SVG
  - 净减少约 2200 行代码
  - 提升代码可维护性和一致性
  - 统一图标样式和尺寸管理

- 恢复 API Key、账号、分组、类型、计费类型等列
- 恢复 Token 详情显示（含缓存读写）
- 恢复首Token时间、耗时列
- 恢复请求ID列及复制功能

- Split UsersView.vue into UserCreateModal, UserEditModal, UserApiKeysModal, etc.
- Split UsageView.vue into UsageStatsCards, UsageFilters, UsageTable, etc.
- Split DashboardView.vue into UserDashboardStats, UserDashboardCharts, etc.
- Split AccountsView.vue into AccountTableActions, AccountTableFilters, etc.
- Standardized TypeScript types across new components to resolve implicit 'any' and 'never[]' errors.
- Improved overall frontend maintainability and code clarity.