Complete CRUD operations for habits

Implement all missing endpoints for full habit management:
- GET /api/v1/habits - List all user habits
- GET /api/v1/habits/{id} - Get specific habit
- PUT /api/v1/habits/{id} - Update habit
- DELETE /api/v1/habits/{id} - Archive habit (soft delete)
- GET /api/v1/habits/{id}/entries - Get habit entry history
- DELETE /api/v1/habits/{id}/entries/{date} - Unmark habit (soft delete entry)

All endpoints include:
- TDD approach with comprehensive test coverage
- JWT authentication and ownership validation
- Proper error handling (404, 403, 400, 500)
- Clean architecture with separated commands/queries

internal/application/queries/get_habit_entries.go

@@ -0,0 +1,73 @@
+package queries
+
+import (
+	"context"
+	"time"
+
+	"apocapoc-api/internal/domain/repositories"
+	"apocapoc-api/internal/shared/errors"
+)
+
+type HabitEntryDTO struct {
+	ID            string
+	HabitID       string
+	ScheduledDate time.Time
+	CompletedAt   time.Time
+	Value         *float64
+}
+
+type GetHabitEntriesQuery struct {
+	HabitID string
+	UserID  string
+}
+
+type GetHabitEntriesHandler struct {
+	habitRepo repositories.HabitRepository
+	entryRepo repositories.HabitEntryRepository
+}
+
+func NewGetHabitEntriesHandler(
+	habitRepo repositories.HabitRepository,
+	entryRepo repositories.HabitEntryRepository,
+) *GetHabitEntriesHandler {
+	return &GetHabitEntriesHandler{
+		habitRepo: habitRepo,
+		entryRepo: entryRepo,
+	}
+}
+
+func (h *GetHabitEntriesHandler) Handle(ctx context.Context, query GetHabitEntriesQuery) ([]HabitEntryDTO, error) {
+	// Verify habit exists and user owns it
+	habit, err := h.habitRepo.FindByID(ctx, query.HabitID)
+	if err != nil {
+		return nil, err
+	}
+
+	if habit.UserID != query.UserID {
+		return nil, errors.ErrUnauthorized
+	}
+
+	// Get all entries for the habit
+	entries, err := h.entryRepo.FindByHabitID(ctx, query.HabitID)
+	if err != nil {
+		return nil, err
+	}
+
+	var result []HabitEntryDTO
+	for _, entry := range entries {
+		// Filter out deleted entries
+		if entry.DeletedAt != nil {
+			continue
+		}
+
+		result = append(result, HabitEntryDTO{
+			ID:            entry.ID,
+			HabitID:       entry.HabitID,
+			ScheduledDate: entry.ScheduledDate,
+			CompletedAt:   entry.CompletedAt,
+			Value:         entry.Value,
+		})
+	}
+
+	return result, nil
+}