feat: migrate Flask API to Go with JWT auth

internal/user/repository.go

@@ -0,0 +1,62 @@
+package user
+
+import (
+	"errors"
+	"rideaware/pkg/database"
+	"gorm.io/gorm"
+)
+
+type Repository struct{}
+
+func NewRepository() *Repository {
+	return &Repository{}
+}
+
+func (r *Repository) CreateUser(user *User) error {
+	return database.DB.Create(user).Error
+}
+
+func (r *Repository) GetUserByUsername(username string) (*User, error) {
+	var user User
+	if err := database.DB.Where("username = ?", username).First(&user).Error; err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil, errors.New("user not found")
+		}
+		return nil, err
+	}
+	return &user, nil
+}
+
+func (r *Repository) GetUserByEmail(email string) (*User, error) {
+	var user User
+	if err := database.DB.Where("email = ?", email).First(&user).Error; err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil, errors.New("user not found")
+		}
+		return nil, err
+	}
+	return &user, nil
+}
+
+func (r *Repository) GetUserByID(id uint) (*User, error) {
+	var user User
+	if err := database.DB.Preload("Profile").Where("id = ?", id).First(&user).Error; err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil, errors.New("user not found")
+		}
+		return nil, err
+	}
+	return &user, nil
+}
+
+func (r *Repository) UpdateUser(user *User) error {
+	return database.DB.Save(user).Error
+}
+
+func (r *Repository) UserExists(username, email string) (bool, error) {
+	var count int64
+	err := database.DB.Model(&User{}).
+		Where("username = ? OR email = ?", username, email).
+		Count(&count).Error
+	return count > 0, err
+}