feat(V0.2): 打卡 / 日历 / 清单模块

- 数据: Habit/CheckIn/CheckList/CheckListItem/CheckListTemplate + 迁移 + 重新生成 client
- 后端: server/checkin/period.js 周期计算(日/周/月/年, 周一起始, Asia/Shanghai)
        /api/checkin/* 打卡项CRUD/打卡/撤销/补打/某日详情/月历
        /api/checklists/* 清单与检查项CRUD/勾选/全选/复制/模板(系统预置出差·回老家)
- 前端: 底部新增「打卡」Tab -> /checkin, 页内三视图
        环形进度 RingProgress + 完成特效(粒子/光晕/触感, 可关闭)
        打卡视图: 待办列表/乐观更新/撤销/新建编辑
        日历视图: 月历网格 + 今天·昨天·明天 + 日期标记/完成率
        清单视图: 场景清单/勾选进度条/模板生成/另存模板/归档
- 文档: docs/V0.2/需求文档.md 补充实现约定(附录B)与接口清单

src/api/checkin.js

@@ -0,0 +1,39 @@
+import { api } from './client.js'
+
+const q = (params) => {
+  const s = new URLSearchParams()
+  Object.entries(params || {}).forEach(([k, v]) => {
+    if (v !== undefined && v !== null && v !== '') s.set(k, v)
+  })
+  const str = s.toString()
+  return str ? '?' + str : ''
+}
+
+// 打卡 / 日历
+export const checkinApi = {
+  habits: (date) => api('/checkin/habits' + q({ date })),
+  day: (date) => api('/checkin/day' + q({ date })),
+  calendar: (month) => api('/checkin/calendar' + q({ month })),
+  createHabit: (body) => api('/checkin/habits', { method: 'POST', body }),
+  updateHabit: (id, body) => api(`/checkin/habits/${id}`, { method: 'PUT', body }),
+  deleteHabit: (id, hard) => api(`/checkin/habits/${id}${hard ? '?hard=1' : ''}`, { method: 'DELETE' }),
+  check: (id, date, note) => api(`/checkin/habits/${id}/check`, { method: 'POST', body: { date, note } }),
+  uncheck: (id, date) => api(`/checkin/habits/${id}/check` + q({ date }), { method: 'DELETE' }),
+}
+
+// 检查清单
+export const checklistApi = {
+  lists: (archived) => api('/checklists' + q({ archived: archived ? 1 : 0 })),
+  list: (id) => api(`/checklists/${id}`),
+  create: (body) => api('/checklists', { method: 'POST', body }),
+  update: (id, body) => api(`/checklists/${id}`, { method: 'PUT', body }),
+  remove: (id) => api(`/checklists/${id}`, { method: 'DELETE' }),
+  duplicate: (id) => api(`/checklists/${id}/duplicate`, { method: 'POST', body: {} }),
+  addItem: (id, body) => api(`/checklists/${id}/items`, { method: 'POST', body }),
+  updateItem: (itemId, body) => api(`/checklists/items/${itemId}`, { method: 'PUT', body }),
+  removeItem: (itemId) => api(`/checklists/items/${itemId}`, { method: 'DELETE' }),
+  checkAll: (id, done) => api(`/checklists/${id}/check-all`, { method: 'POST', body: { done } }),
+  templates: () => api('/checklists/templates'),
+  createTemplate: (body) => api('/checklists/templates', { method: 'POST', body }),
+  removeTemplate: (id) => api(`/checklists/templates/${id}`, { method: 'DELETE' }),
+}