Add pagination support to GET /api/v1/habits endpoint

- Create pagination package with Params and Response structs
- Add FindActiveByUserIDWithPagination and CountActiveByUserID methods to HabitRepository interface
- Implement pagination in SQLite repository using LIMIT and OFFSET
- Update GetUserHabitsHandler to support optional pagination parameters
- Modify HTTP endpoint to parse 'page' and 'page_size' query params (default: page=1, page_size=50, max=100)
- Add GetUserHabitsResponse DTO with pagination metadata
- Maintain backward compatibility - endpoint works with and without pagination params
- Add comprehensive tests for pagination logic in repository, handler, and pagination package
- Update all mock repositories to implement new pagination methods

internal/domain/repositories/habit_repository.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"apocapoc-api/internal/domain/entities"
+	"apocapoc-api/internal/shared/pagination"
 )
 
 type HabitRepository interface {
@@ -11,6 +12,8 @@ type HabitRepository interface {
 	FindByID(ctx context.Context, id string) (*entities.Habit, error)
 	FindByUserID(ctx context.Context, userID string) ([]*entities.Habit, error)
 	FindActiveByUserID(ctx context.Context, userID string) ([]*entities.Habit, error)
+	FindActiveByUserIDWithPagination(ctx context.Context, userID string, params pagination.Params) ([]*entities.Habit, error)
+	CountActiveByUserID(ctx context.Context, userID string) (int, error)
 	Update(ctx context.Context, habit *entities.Habit) error
 	Delete(ctx context.Context, id string) error
 }