Add data export functionality with gzip compression

- Add FindByUserID method to HabitEntryRepository (JOIN with habits)
- Implement ExportUserDataHandler to export all user data
- Add GET /api/v1/export endpoint with gzip compression
- Apply strict rate limiting (1 export per hour per user)
- Export includes all habits (active + archived) and entries
- Add i18n translations for export errors (en/es)
- Update all test mocks to implement new repository method
- Export format: JSON with gzip (~10x compression ratio)

internal/application/commands/mark_habit_test.go

@@ -40,6 +40,10 @@ func (m *mockEntryRepo) FindByHabitIDAndDateRange(ctx context.Context, habitID s
 	return nil, nil
 }
 
+func (m *mockEntryRepo) FindByUserID(ctx context.Context, userID string) ([]*entities.HabitEntry, error) {
+	return nil, nil
+}
+
 func (m *mockEntryRepo) FindPendingByHabitID(ctx context.Context, habitID string, beforeDate time.Time) ([]*entities.HabitEntry, error) {
 	return nil, nil
 }

internal/application/queries/export_user_data_handler.go

@@ -0,0 +1,104 @@
+package queries
+
+import (
+	"context"
+	"time"
+
+	"apocapoc-api/internal/domain/repositories"
+	"apocapoc-api/internal/domain/value_objects"
+)
+
+type ExportHabitDTO struct {
+	ID            string                   `json:"id"`
+	Name          string                   `json:"name"`
+	Description   string                   `json:"description"`
+	Type          value_objects.HabitType  `json:"type"`
+	Frequency     value_objects.Frequency  `json:"frequency"`
+	SpecificDays  []int                    `json:"specific_days,omitempty"`
+	SpecificDates []int                    `json:"specific_dates,omitempty"`
+	CarryOver     bool                     `json:"carry_over"`
+	IsNegative    bool                     `json:"is_negative"`
+	TargetValue   *float64                 `json:"target_value,omitempty"`
+	CreatedAt     time.Time                `json:"created_at"`
+	ArchivedAt    *time.Time               `json:"archived_at,omitempty"`
+}
+
+type ExportEntryDTO struct {
+	ID            string     `json:"id"`
+	HabitID       string     `json:"habit_id"`
+	ScheduledDate time.Time  `json:"scheduled_date"`
+	CompletedAt   time.Time  `json:"completed_at"`
+	Value         *float64   `json:"value,omitempty"`
+}
+
+type ExportUserDataResult struct {
+	ExportedAt time.Time        `json:"exported_at"`
+	Habits     []ExportHabitDTO `json:"habits"`
+	Entries    []ExportEntryDTO `json:"entries"`
+}
+
+type ExportUserDataQuery struct {
+	UserID string
+}
+
+type ExportUserDataHandler struct {
+	habitRepo repositories.HabitRepository
+	entryRepo repositories.HabitEntryRepository
+}
+
+func NewExportUserDataHandler(
+	habitRepo repositories.HabitRepository,
+	entryRepo repositories.HabitEntryRepository,
+) *ExportUserDataHandler {
+	return &ExportUserDataHandler{
+		habitRepo: habitRepo,
+		entryRepo: entryRepo,
+	}
+}
+
+func (h *ExportUserDataHandler) Handle(ctx context.Context, query ExportUserDataQuery) (*ExportUserDataResult, error) {
+	habits, err := h.habitRepo.FindByUserID(ctx, query.UserID)
+	if err != nil {
+		return nil, err
+	}
+
+	entries, err := h.entryRepo.FindByUserID(ctx, query.UserID)
+	if err != nil {
+		return nil, err
+	}
+
+	habitDTOs := make([]ExportHabitDTO, 0, len(habits))
+	for _, habit := range habits {
+		habitDTOs = append(habitDTOs, ExportHabitDTO{
+			ID:            habit.ID,
+			Name:          habit.Name,
+			Description:   habit.Description,
+			Type:          habit.Type,
+			Frequency:     habit.Frequency,
+			SpecificDays:  habit.SpecificDays,
+			SpecificDates: habit.SpecificDates,
+			CarryOver:     habit.CarryOver,
+			IsNegative:    habit.IsNegative,
+			TargetValue:   habit.TargetValue,
+			CreatedAt:     habit.CreatedAt,
+			ArchivedAt:    habit.ArchivedAt,
+		})
+	}
+
+	entryDTOs := make([]ExportEntryDTO, 0, len(entries))
+	for _, entry := range entries {
+		entryDTOs = append(entryDTOs, ExportEntryDTO{
+			ID:            entry.ID,
+			HabitID:       entry.HabitID,
+			ScheduledDate: entry.ScheduledDate,
+			CompletedAt:   entry.CompletedAt,
+			Value:         entry.Value,
+		})
+	}
+
+	return &ExportUserDataResult{
+		ExportedAt: time.Now(),
+		Habits:     habitDTOs,
+		Entries:    entryDTOs,
+	}, nil
+}

internal/application/queries/get_todays_habits_test.go

@@ -73,6 +73,10 @@ func (m *mockEntryRepo) FindByHabitIDAndDateRange(ctx context.Context, habitID s
 	return result, nil
 }
 
+func (m *mockEntryRepo) FindByUserID(ctx context.Context, userID string) ([]*entities.HabitEntry, error) {
+	return nil, nil
+}
+
 func (m *mockEntryRepo) FindPendingByHabitID(ctx context.Context, habitID string, beforeDate time.Time) ([]*entities.HabitEntry, error) {
 	return nil, nil
 }