feat(pool): 增加 OAuth 账号池管理功能

- 新增 pool manager / strategy / health_policy / cost_tracker / redis_ops 等核心模块
- 新增 pool admin API 路由与 schemas
- 新增 OAuth 账号类型解析 (oauth_plan)
- 前端增加 PoolManagement 页面、PoolConfigDialog、PoolImportDialog、PoolStatusCard 组件
- 补充 pool config / cost tracker / health policy / manager / strategy / trace 等测试

frontend/src/utils/oauthPlanType.ts

@@ -0,0 +1,70 @@
+const PLAN_TYPE_LABELS: Record<string, string> = {
+  free: 'Free',
+  plus: 'Plus',
+  team: 'Team',
+  enterprise: 'Enterprise',
+  paid: 'Paid',
+  pro: 'Pro',
+  'pro+': 'Pro+',
+  power: 'Power',
+  ultra: 'Ultra',
+}
+
+const PLAN_TYPE_CLASS_NAMES: Record<string, string> = {
+  plus: 'border-green-500/50 text-green-600 dark:text-green-400',
+  pro: 'border-blue-500/50 text-blue-600 dark:text-blue-400',
+  free: 'border-primary/50 text-primary',
+  paid: 'border-blue-500/50 text-blue-600 dark:text-blue-400',
+  team: 'border-purple-500/50 text-purple-600 dark:text-purple-400',
+  enterprise: 'border-amber-500/50 text-amber-600 dark:text-amber-400',
+  ultra: 'border-amber-500/50 text-amber-600 dark:text-amber-400',
+  'pro+': 'border-purple-500/50 text-purple-600 dark:text-purple-400',
+  power: 'border-amber-500/50 text-amber-600 dark:text-amber-400',
+}
+
+export function normalizeOAuthPlanType(planType?: string | null): string | null {
+  if (typeof planType !== 'string') {
+    return null
+  }
+
+  const normalized = planType.trim().toLowerCase()
+  if (!normalized) {
+    return null
+  }
+  return normalized
+}
+
+export function formatOAuthPlanType(planType?: string | null): string {
+  const normalized = normalizeOAuthPlanType(planType)
+  if (!normalized) {
+    return ''
+  }
+
+  const knownLabel = PLAN_TYPE_LABELS[normalized]
+  if (knownLabel) {
+    return knownLabel
+  }
+
+  return normalized
+    .replace(/[_-]+/g, ' ')
+    .split(/\s+/)
+    .filter(Boolean)
+    .map(part => part[0].toUpperCase() + part.slice(1))
+    .join(' ')
+}
+
+export function getOAuthPlanTypeClass(planType?: string | null): string {
+  const normalized = normalizeOAuthPlanType(planType)
+  if (!normalized) {
+    return ''
+  }
+  return PLAN_TYPE_CLASS_NAMES[normalized] || ''
+}
+
+export function isNonFreeOAuthPlan(planType?: string | null): boolean {
+  const normalized = normalizeOAuthPlanType(planType)
+  if (!normalized) {
+    return false
+  }
+  return normalized !== 'free'
+}