Merge branch 'develop' into refactor/use-step4-title-split

主文件 251→75 行（-70%），拆分为：
- useAiTitleGenerator: AI 标题生成、刷新、选择逻辑
- useTitleStyleUpdaters: 标题文字/位置/字体/样式等所有设置更新
- index: 组合入口 + 标题库数据查询

导入路径保持向后兼容

apps/web/src/api/subscription.ts

@@ -1,6 +1,8 @@
 /**
- * 订阅相关类型定义
+ * 订阅 API 模块
+ * 对接后端订阅管理接口
  */
+import apiClient from "./client"
 
 /** 套餐类型 */
 export type PlanType = "free" | "standard" | "pro" | "enterprise"
@@ -63,3 +65,42 @@ export interface ChangePlanResponse {
   message: string
   new_subscription?: SubscriptionInfo
 }
+
+// ============ API 函数 ============
+
+/** 获取当前订阅信息 */
+export const getCurrentSubscription = async (): Promise<SubscriptionInfo> => {
+  const response = await apiClient.get("/subscription/current")
+  return response.data
+}
+
+/** 获取账单记录列表 */
+export const getBillingRecords = async (): Promise<BillingRecord[]> => {
+  const response = await apiClient.get("/subscription/billing-records")
+  return response.data
+}
+
+/** 升级/降级套餐 */
+export const changePlan = async (request: ChangePlanRequest): Promise<ChangePlanResponse> => {
+  const response = await apiClient.post("/subscription/change-plan", request)
+  return response.data
+}
+
+/** 取消订阅 */
+export const cancelSubscription = async (): Promise<{
+  success: boolean
+  message: string
+}> => {
+  const response = await apiClient.post("/subscription/cancel")
+  return response.data
+}
+
+/** 切换自动续费 */
+export const toggleAutoRenew = async (
+  enabled: boolean,
+): Promise<{ success: boolean; message: string }> => {
+  const response = await apiClient.post("/subscription/toggle-auto-renew", {
+    enabled,
+  })
+  return response.data
+}

apps/web/src/api/subscription/index.ts

@@ -1,26 +0,0 @@
-/**
- * 订阅 API — 目录化入口
- * 保持与原 subscription.ts 相同导出，向后兼容
- */
-
-// 类型
-export type {
-  PlanType,
-  SubscriptionStatus,
-  BillingStatus,
-  BillingCycle,
-  Plan,
-  SubscriptionInfo,
-  BillingRecord,
-  ChangePlanRequest,
-  ChangePlanResponse,
-} from "./types"
-
-// API 函数
-export {
-  getCurrentSubscription,
-  getBillingRecords,
-  changePlan,
-  cancelSubscription,
-  toggleAutoRenew,
-} from "./subscription"

apps/web/src/api/subscription/subscription.ts

@@ -1,47 +0,0 @@
-/**
- * 订阅相关 API 函数
- */
-import apiClient from "../client"
-import type {
-  BillingRecord,
-  ChangePlanRequest,
-  ChangePlanResponse,
-  SubscriptionInfo,
-} from "./types"
-
-/** 获取当前订阅信息 */
-export const getCurrentSubscription = async (): Promise<SubscriptionInfo> => {
-  const response = await apiClient.get("/subscription/current")
-  return response.data
-}
-
-/** 获取账单记录列表 */
-export const getBillingRecords = async (): Promise<BillingRecord[]> => {
-  const response = await apiClient.get("/subscription/billing-records")
-  return response.data
-}
-
-/** 升级/降级套餐 */
-export const changePlan = async (request: ChangePlanRequest): Promise<ChangePlanResponse> => {
-  const response = await apiClient.post("/subscription/change-plan", request)
-  return response.data
-}
-
-/** 取消订阅 */
-export const cancelSubscription = async (): Promise<{
-  success: boolean
-  message: string
-}> => {
-  const response = await apiClient.post("/subscription/cancel")
-  return response.data
-}
-
-/** 切换自动续费 */
-export const toggleAutoRenew = async (
-  enabled: boolean,
-): Promise<{ success: boolean; message: string }> => {
-  const response = await apiClient.post("/subscription/toggle-auto-renew", {
-    enabled,
-  })
-  return response.data
-}