feat(首页): 登录后不再弹「登录速报」，上次来做了什么、哪道还没做对放进首页，带「接着做」

- 新接口 /me/last-visit：上次登录到这次登录之间的题库提交，不调 AI（原来要同步等模型最长 60 秒弹框才出来）
- 班里今天在做时让位给班里卡，只在卡底留一句；班里那天就是上次来那天时两张卡合成一张
- 第一次登录说「欢迎来到判题狗」，隔了 30 天以上说「好久不见」
- 删掉弹框、store 和 /ai/login-summary

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/web/CLAUDE.md

@@ -58,7 +58,7 @@ API 调用不按模块分：学生端全在 `oj/api.ts`、后台全在 `admin/ap
 跨端的（登录、资料、标签、验证码）在 `shared/api.ts`。
 
 Shared logic lives in `shared/`:
-- `store/` — Pinia stores: `user` (auth/roles), `config` (site-wide settings), `authModal` (login/signup form state), `loginSummary` (AI activity summary), `collab` (help-request queue + collab room), `achievement` (解锁弹窗队列), `myFlowchart` (题面「你画的流程图」那张 A/S 图的 mermaid 源码)
+- `store/` — Pinia stores: `user` (auth/roles), `config` (site-wide settings), `authModal` (login/signup form state), `collab` (help-request queue + collab room), `achievement` (解锁弹窗队列), `myFlowchart` (题面「你画的流程图」那张 A/S 图的 mermaid 源码)
 - `composables/` — `aiStream`, `pagination` (URL-synced), `websocket` (reconnect + heartbeat), `collabDoc` (Yjs binding for the collab channel), `configUpdate` (WS-pushed config sync), `useMermaid` (lazy Mermaid render), `darkTransition` (View Transitions，111 以下走降级分支), `hiddenStudents` (课堂看板的「请假隐藏」), `chartTheme`, `breakpoints`, `maxkb`, `learnProgress`, `rarity`
 - `layout/` — `default.vue` and `admin.vue` layout wrappers
 - `api.ts` — shared API calls (auth, profile, tags, captcha)