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

.env.example

@@ -2,7 +2,7 @@
 # Copy this file to `.env` and fill values before running locally
 
 # Redis connection
-REDIS_HOST=localhost          # Redis host (default: localhost)
+REDIS_HOST=10.8.8.109          # Redis host (default: localhost)
 REDIS_PORT=6379               # Redis port (default: 6379)
 REDIS_PASSWORD=               # Redis password (leave empty if not set)
 REDIS_DB=0                    # Redis database number (default: 0)
@@ -12,5 +12,13 @@ REDIS_CONNECT_TIMEOUT_MS=2000 # Connection timeout in ms (default: 2000)
 # Optional: port for backend server. Current default in code is 3001 but you can override it here.
 PORT=3001
 
+# Command control (HTTP)
+# Timeout for calling target project APIs (ms)
+COMMAND_API_TIMEOUT_MS=5000
+
+# Heartbeat liveness
+# If now - lastActiveAt > threshold, treat project as offline (ms)
+HEARTBEAT_OFFLINE_THRESHOLD_MS=10000
+
 # Node environment (development|production)
 NODE_ENV=development