feat: 导入导出错误信息 Markdown 渲染升级

Phase 1: 共用类型定义
- apps/server/src/common/import-result.types.ts — ImportRowError + ImportResult<T>
- apps/admin/src/types/import.ts — 前端对应类型 + ImportDisplayConfig

Phase 2: 后端增强
- students.service.ts — batchImport/matchImport 改为 ImportResult 格式
  · 每行跳过时收集 ImportRowError（code + reason）
  · reason 支持 markdown 标记（**字段名** / `值`）
- archive.service.ts — batchImportArchive 统一用 ImportResult 格式
  · 各 Sheet 错误使用标准 error code
- archive.controller.ts — 日志使用新的 success 字段

Phase 3: 前端基础
- 安装 react-markdown
- ImportResultModal 组件（共用导入结果弹窗）
  · Statistic 成功统计 + Table 错误明细
  · 原因列支持 react-markdown 渲染（粗体字段名、等宽代码值）
  · 错误类型用 Tag 颜色区分
- api/index.ts — 403 错误从 console.warn 改为 message.warning 用户可见

Phase 4: 前端集成
- Students/index.tsx — 替换硬编码导入结果弹窗
  · 删除'后端只返回统计汇总'注释和跳过原因 hardcode
  · 新格式自动使用 ImportResultModal，旧格式兼容
- StudentProfileContent/index.tsx — 替换内联导入 Modal 为 ImportResultModal

.agents/skills/using-superpowers/references/codex-tools.md

@@ -0,0 +1,39 @@
+## Subagent dispatch requires multi-agent support
+
+Add to your Codex config (`~/.codex/config.toml`):
+
+```toml
+[features]
+multi_agent = true
+```
+
+This enables `spawn_agent`, `wait_agent`, and `close_agent` for skills like `dispatching-parallel-agents` and `subagent-driven-development`. When using subagent-driven-development, you should always close implementer and reviewer subagents when they have finished all their work.
+
+## Environment Detection
+
+Skills that create worktrees or finish branches should detect their
+environment with read-only git commands before proceeding:
+
+```bash
+GIT_DIR=$(cd "$(git rev-parse --git-dir)" 2>/dev/null && pwd -P)
+GIT_COMMON=$(cd "$(git rev-parse --git-common-dir)" 2>/dev/null && pwd -P)
+BRANCH=$(git branch --show-current)
+```
+
+- `GIT_DIR != GIT_COMMON` → already in a linked worktree (skip creation)
+- `BRANCH` empty → detached HEAD (cannot branch/push/PR from sandbox)
+
+See `using-git-worktrees` Step 0 and `finishing-a-development-branch`
+Step 1 for how each skill uses these signals.
+
+## Codex App Finishing
+
+When the sandbox blocks branch/push operations (detached HEAD in an
+externally managed worktree), the agent commits all work and informs
+the user to use the App's native controls:
+
+- **"Create branch"** — names the branch, then commit/push/PR via App UI
+- **"Hand off to local"** — transfers work to the user's local checkout
+
+The agent can still run tests, stage files, and output suggested branch
+names, commit messages, and PR descriptions for the user to copy.