Add refresh token authentication system

Implement complete refresh token flow for improved security:
- Short-lived access tokens (configurable, default 1h)
- Long-lived refresh tokens (configurable, default 7d)
- Automatic token rotation on refresh
- Token revocation for proper logout

Domain layer:
- Add RefreshToken entity with validation and revocation
- Add RefreshTokenRepository interface

Application layer:
- Add RefreshTokenHandler for token refresh operations
- Add RevokeTokenHandler for single token revocation
- Add RevokeAllTokensHandler for user-wide revocation

Infrastructure layer:
- Implement SQLite RefreshTokenRepository
- Add refresh_tokens table migration with indexes
- Add parseDuration helper for flexible time configuration

HTTP layer:
- Add POST /api/v1/auth/refresh endpoint
- Add POST /api/v1/auth/logout endpoint
- Update login/register to return refresh tokens
- Improve Swagger documentation with clear descriptions

Configuration:
- Update .env.example with secure token expiry defaults
- Add support for minute/hour/day duration formats

Tests:
- Fix test suite to work with new signatures
- All existing tests passing

internal/application/queries/refresh_token.go

@@ -0,0 +1,82 @@
+package queries
+
+import (
+	"context"
+	"crypto/rand"
+	"encoding/base64"
+	"fmt"
+	"time"
+
+	"apocapoc-api/internal/domain/entities"
+	"apocapoc-api/internal/domain/repositories"
+	"apocapoc-api/internal/shared/errors"
+)
+
+type RefreshTokenQuery struct {
+	RefreshToken string
+}
+
+type RefreshTokenResult struct {
+	UserID   string
+	Email    string
+	Timezone string
+}
+
+type RefreshTokenHandler struct {
+	refreshTokenRepo repositories.RefreshTokenRepository
+	userRepo         repositories.UserRepository
+}
+
+func NewRefreshTokenHandler(
+	refreshTokenRepo repositories.RefreshTokenRepository,
+	userRepo repositories.UserRepository,
+) *RefreshTokenHandler {
+	return &RefreshTokenHandler{
+		refreshTokenRepo: refreshTokenRepo,
+		userRepo:         userRepo,
+	}
+}
+
+func (h *RefreshTokenHandler) Handle(ctx context.Context, query RefreshTokenQuery) (*RefreshTokenResult, error) {
+	if query.RefreshToken == "" {
+		return nil, errors.ErrInvalidInput
+	}
+
+	refreshToken, err := h.refreshTokenRepo.FindByToken(ctx, query.RefreshToken)
+	if err != nil {
+		return nil, errors.ErrNotFound
+	}
+
+	if !refreshToken.IsValid() {
+		return nil, errors.ErrNotFound
+	}
+
+	user, err := h.userRepo.FindByID(ctx, refreshToken.UserID)
+	if err != nil {
+		return nil, errors.ErrNotFound
+	}
+
+	return &RefreshTokenResult{
+		UserID:   user.ID,
+		Email:    user.Email,
+		Timezone: user.Timezone,
+	}, nil
+}
+
+func GenerateRefreshToken() (string, error) {
+	b := make([]byte, 32)
+	if _, err := rand.Read(b); err != nil {
+		return "", fmt.Errorf("failed to generate refresh token: %w", err)
+	}
+	return base64.URLEncoding.EncodeToString(b), nil
+}
+
+func CreateRefreshToken(userID string, expiryDuration time.Duration) (*entities.RefreshToken, error) {
+	token, err := GenerateRefreshToken()
+	if err != nil {
+		return nil, err
+	}
+
+	expiresAt := time.Now().Add(expiryDuration)
+	return entities.NewRefreshToken(userID, token, expiresAt), nil
+}