feat: 重构项目心跳数据结构并实现项目列表API

- 新增统一项目列表Redis键和迁移工具
- 实现GET /api/projects端点获取项目列表
- 实现POST /api/projects/migrate端点支持数据迁移
- 更新前端ProjectSelector组件使用真实项目数据
- 扩展projectStore状态管理
- 更新相关文档和OpenSpec规范
- 添加测试用例验证新功能

.github/prompts/openspec-apply.prompt.md

@@ -3,14 +3,18 @@ description: Implement an approved OpenSpec change and keep tasks in sync.
 ---
 
 $ARGUMENTS
+
 <!-- OPENSPEC:START -->
+
 **Guardrails**
+
 - Favor straightforward, minimal implementations first and add complexity only when it is requested or clearly required.
 - Keep changes tightly scoped to the requested outcome.
 - Refer to `openspec/AGENTS.md` (located inside the `openspec/` directory—run `ls openspec` or `openspec update` if you don't see it) if you need additional OpenSpec conventions or clarifications.
 
 **Steps**
 Track these steps as TODOs and complete them one by one.
+
 1. Read `changes/<id>/proposal.md`, `design.md` (if present), and `tasks.md` to confirm scope and acceptance criteria.
 2. Work through tasks sequentially, keeping edits minimal and focused on the requested change.
 3. Confirm completion before updating statuses—make sure every item in `tasks.md` is finished.
@@ -18,5 +22,6 @@ Track these steps as TODOs and complete them one by one.
 5. Reference `openspec list` or `openspec show <item>` when additional context is required.
 
 **Reference**
+
 - Use `openspec show <id> --json --deltas-only` if you need additional context from the proposal while implementing.
 <!-- OPENSPEC:END -->