feat: initial lifelog project

- 待办事项（支持优先级、截止日期）
- 每日记录（上午/下午/晚上分条目）
- Go后端 + Gin + GORM + MySQL
- React前端 + TailwindCSS

internal/service/service.go

@@ -0,0 +1,99 @@
+package service
+
+import (
+	"errors"
+	"lifelog/internal/model"
+	"lifelog/internal/repository"
+	"time"
+)
+
+type TodoService struct {
+	repo *repository.TodoRepository
+}
+
+func NewTodoService(repo *repository.TodoRepository) *TodoService {
+	return &TodoService{repo: repo}
+}
+
+func (s *TodoService) GetAll() ([]model.Todo, error) {
+	return s.repo.GetAll()
+}
+
+func (s *TodoService) Create(title string, priority int, dueDate *time.Time) (*model.Todo, error) {
+	todo := &model.Todo{
+		Title:    title,
+		Done:     false,
+		Priority: priority,
+		DueDate:  dueDate,
+	}
+	err := s.repo.Create(todo)
+	return todo, err
+}
+
+func (s *TodoService) Update(id uint64, title string, priority int, done bool, dueDate *time.Time) (*model.Todo, error) {
+	todo, err := s.repo.GetByID(id)
+	if err != nil {
+		return nil, err
+	}
+	todo.Title = title
+	todo.Priority = priority
+	todo.Done = done
+	todo.DueDate = dueDate
+	err = s.repo.Update(todo)
+	return todo, err
+}
+
+func (s *TodoService) ToggleDone(id uint64) (*model.Todo, error) {
+	todo, err := s.repo.GetByID(id)
+	if err != nil {
+		return nil, err
+	}
+	todo.Done = !todo.Done
+	err = s.repo.Update(todo)
+	return todo, err
+}
+
+func (s *TodoService) Delete(id uint64) error {
+	return s.repo.Delete(id)
+}
+
+type DailyLogService struct {
+	repo *repository.DailyLogRepository
+}
+
+func NewDailyLogService(repo *repository.DailyLogRepository) *DailyLogService {
+	return &DailyLogService{repo: repo}
+}
+
+func (s *DailyLogService) GetByDate(date string) (*model.DailyLog, error) {
+	log, err := s.repo.GetByDate(date)
+	if err != nil {
+		return nil, err
+	}
+	if log == nil {
+		// 返回空记录
+		return &model.DailyLog{Date: date}, nil
+	}
+	return log, nil
+}
+
+func (s *DailyLogService) GetRecent(limit int) ([]model.DailyLog, error) {
+	if limit <= 0 {
+		limit = 30
+	}
+	return s.repo.GetRecent(limit)
+}
+
+func (s *DailyLogService) Save(date, morning, afternoon, evening string) (*model.DailyLog, error) {
+	if date == "" {
+		return nil, errors.New("date is required")
+	}
+	log := &model.DailyLog{
+		Date:      date,
+		Morning:   morning,
+		Afternoon: afternoon,
+		Evening:   evening,
+	}
+	err := s.repo.Upsert(log)
+	return log, err
+}