refactor: 企业级目录重构与播放/关于页体验升级

- 按 app / shared / entities / features 分层，路由懒加载并抽出布局组件
- 请求层改为可插拔拦截器，统一错误类型、超时取消与端点拆分
- 抽取播放器、骨架屏、网格等复用组件，点赞收藏接入统一交互反馈
- 关于页重做为无边框极光风格，补充 iOS / Google Play 下载入口
- 修复播放页滚轮切集吞事件、页面误滚动、后台持续播放与声音记忆问题
- 语言按本地偏好与 IP 识别，国旗改为内联 SVG
- 清理未使用的旧站点文件，补充 ESLint 配置

src/shared/api/errors.js

@@ -0,0 +1,36 @@
+// Author: fruit.com.cn
+export class ApiError extends Error {
+  constructor(message, { status = 0, code = null, path = '', cause } = {}) {
+    super(message);
+    this.name = 'ApiError';
+    this.status = status;
+    this.code = code;
+    this.path = path;
+    this.cause = cause;
+  }
+}
+
+export class TimeoutError extends ApiError {
+  constructor(path, timeout) {
+    super(`Request timed out after ${timeout}ms`, { path });
+    this.name = 'TimeoutError';
+  }
+}
+
+export class NetworkError extends ApiError {
+  constructor(path, cause) {
+    super('Network request failed', { path, cause });
+    this.name = 'NetworkError';
+  }
+}
+
+export class CanceledError extends ApiError {
+  constructor(path) {
+    super('Request canceled', { path });
+    this.name = 'CanceledError';
+  }
+}
+
+export function isCanceled(error) {
+  return error instanceof CanceledError || error?.name === 'CanceledError' || error?.name === 'AbortError';
+}