feat(自学): 自学重做——首页课程地图、读一课按项目分目录、代码块就地运行、学完给题做

- 顶栏「自学」进新的自学首页 /learn：接着学（按服务端记录，不再串到上一个学生）+ 按项目分组的课程地图
- 读一课：左边目录按项目折叠，正文加宽，右边本课大纲带练一练标记；去掉了不能运行的示例代码栏
- 正文里的代码块能改能运行，报错用题目页那套中文解释；读输入的代码出输入框
- 课末：练一练做到几道 → 学完了 → 老师挑的几道题（必会标出来）→ 下一课
- 练一练统一成绿色提交、结果一行字；手机版目录从底部弹出
- 后台：教程列表按项目分组拖动排序，编辑页左写右看、练一练插到光标处、挑相关题；
  自学情况改成方块格 + 还没打开过的名单

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

apps/web/CLAUDE.md

@@ -59,7 +59,7 @@ API 调用不按模块分：学生端全在 `oj/api.ts`、后台全在 `admin/ap
 
 Shared logic lives in `shared/`:
 - `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), `leaveStudents` (课堂看板的「请假」), `chartTheme`, `breakpoints`, `maxkb`, `learnProgress`, `rarity`
+- `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), `leaveStudents` (课堂看板的「请假」), `chartTheme`, `breakpoints`, `maxkb`, `rarity`
 - `layout/` — `default.vue` and `admin.vue` layout wrappers
 - `api.ts` — shared API calls (auth, profile, tags, captcha)