refactor: 个人自用，移除登录与云同步全链路

站点只给本人用，云乐坊 SSO 授权、收藏/历史云同步、获客归因和账号切换记账都没有收益，却被登录状态检查和同步失败提示持续打扰。

- 删除 useYunlefunAuth / yunlefunAuth / yunlefunSsoConfig / yunlefunAuth 适配器、useUserDataSync / userDataSync / userData 适配器、三个 client 插件与 /auth/callback 回调页
- 抽出 adapters/cloudbase.ts，让「反馈一下」和匿名筛选信号不再依赖登录态；cook-feedback 云函数保留
- 删除 cook-user-data 云函数与 cook_user_data 权限规则，移除 @yunlefun/sso 依赖
- 「我的」页删掉登录按钮、账号卡、四个统计格和退出登录；「关于」页删掉项目作者、致谢名单和上游宣传链接
- 本地收藏/历史与导出导入保留，删除同步专用的 lastUid 记账

取舍见 docs/decisions/0005-drop-login-and-sync.md

apps/web/app/composables/store/userDataMeta.ts

@@ -3,21 +3,18 @@ import { useStorage } from '@vueuse/core'
 import { namespace } from '~/constants'
 
 /**
- * Sync bookkeeping kept next to `cook:favorites` and `cook:history`, which stay
- * in their original format. Deletions are recorded even when logged out so they
- * can be applied to the cloud after the next login.
+ * Deletion bookkeeping kept next to `cook:favorites` and `cook:history`, which
+ * stay in their original format. Deletions are recorded so they survive an
+ * export/import round trip instead of resurrecting removed records.
  */
 export interface UserDataMeta {
   favoriteRemovals: FavoriteRemoval[]
   historyRemovals: HistoryRemoval[]
   historyClearedAt: number
-  /** The account this device last synced with. */
-  lastUid: string
 }
 
 export const userDataMeta = useStorage<UserDataMeta>(`${namespace}:sync`, {
   favoriteRemovals: [],
   historyRemovals: [],
   historyClearedAt: 0,
-  lastUid: '',
 }, undefined, { mergeDefaults: true })