Migrate from Gin to Echo framework and add comprehensive integration tests

Major changes:
- Migrate all handlers from Gin to Echo framework
- Add new apperrors, echohelpers, and validator packages
- Update middleware for Echo compatibility
- Add ArchivedHandler to task categorization chain (archived tasks go to cancelled_tasks column)
- Add 6 new integration tests:
  - RecurringTaskLifecycle: NextDueDate advancement for weekly/monthly tasks
  - MultiUserSharing: Complex sharing with user removal
  - TaskStateTransitions: All state transitions and kanban column changes
  - DateBoundaryEdgeCases: Threshold boundary testing
  - CascadeOperations: Residence deletion cascade effects
  - MultiUserOperations: Shared residence collaboration
- Add single-purpose repository functions for kanban columns (GetOverdueTasks, GetDueSoonTasks, etc.)
- Fix RemoveUser route param mismatch (userId -> user_id)
- Fix determineExpectedColumn helper to correctly prioritize in_progress over overdue

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/services/notification_service.go

@@ -8,6 +8,7 @@ import (
 
 	"gorm.io/gorm"
 
+	"github.com/treytartt/casera-api/internal/apperrors"
 	"github.com/treytartt/casera-api/internal/models"
 	"github.com/treytartt/casera-api/internal/push"
 	"github.com/treytartt/casera-api/internal/repositories"
@@ -15,8 +16,11 @@ import (
 
 // Notification-related errors
 var (
+	// Deprecated: Use apperrors.NotFound("error.notification_not_found") instead
 	ErrNotificationNotFound = errors.New("notification not found")
+	// Deprecated: Use apperrors.NotFound("error.device_not_found") instead
 	ErrDeviceNotFound       = errors.New("device not found")
+	// Deprecated: Use apperrors.BadRequest("error.invalid_platform") instead
 	ErrInvalidPlatform      = errors.New("invalid platform, must be 'ios' or 'android'")
 )
 
@@ -40,7 +44,7 @@ func NewNotificationService(notificationRepo *repositories.NotificationRepositor
 func (s *NotificationService) GetNotifications(userID uint, limit, offset int) ([]NotificationResponse, error) {
 	notifications, err := s.notificationRepo.FindByUser(userID, limit, offset)
 	if err != nil {
-		return nil, err
+		return nil, apperrors.Internal(err)
 	}
 
 	result := make([]NotificationResponse, len(notifications))
@@ -52,7 +56,11 @@ func (s *NotificationService) GetNotifications(userID uint, limit, offset int) (
 
 // GetUnreadCount gets the count of unread notifications
 func (s *NotificationService) GetUnreadCount(userID uint) (int64, error) {
-	return s.notificationRepo.CountUnread(userID)
+	count, err := s.notificationRepo.CountUnread(userID)
+	if err != nil {
+		return 0, apperrors.Internal(err)
+	}
+	return count, nil
 }
 
 // MarkAsRead marks a notification as read
@@ -60,21 +68,27 @@ func (s *NotificationService) MarkAsRead(notificationID, userID uint) error {
 	notification, err := s.notificationRepo.FindByID(notificationID)
 	if err != nil {
 		if errors.Is(err, gorm.ErrRecordNotFound) {
-			return ErrNotificationNotFound
+			return apperrors.NotFound("error.notification_not_found")
 		}
-		return err
+		return apperrors.Internal(err)
 	}
 
 	if notification.UserID != userID {
-		return ErrNotificationNotFound
+		return apperrors.NotFound("error.notification_not_found")
 	}
 
-	return s.notificationRepo.MarkAsRead(notificationID)
+	if err := s.notificationRepo.MarkAsRead(notificationID); err != nil {
+		return apperrors.Internal(err)
+	}
+	return nil
 }
 
 // MarkAllAsRead marks all notifications as read
 func (s *NotificationService) MarkAllAsRead(userID uint) error {
-	return s.notificationRepo.MarkAllAsRead(userID)
+	if err := s.notificationRepo.MarkAllAsRead(userID); err != nil {
+		return apperrors.Internal(err)
+	}
+	return nil
 }
 
 // CreateAndSendNotification creates a notification and sends it via push
@@ -82,7 +96,7 @@ func (s *NotificationService) CreateAndSendNotification(ctx context.Context, use
 	// Check user preferences
 	prefs, err := s.notificationRepo.GetOrCreatePreferences(userID)
 	if err != nil {
-		return err
+		return apperrors.Internal(err)
 	}
 
 	// Check if notification type is enabled
@@ -101,13 +115,13 @@ func (s *NotificationService) CreateAndSendNotification(ctx context.Context, use
 	}
 
 	if err := s.notificationRepo.Create(notification); err != nil {
-		return err
+		return apperrors.Internal(err)
 	}
 
 	// Get device tokens
 	iosTokens, androidTokens, err := s.notificationRepo.GetActiveTokensForUser(userID)
 	if err != nil {
-		return err
+		return apperrors.Internal(err)
 	}
 
 	// Convert data for push
@@ -128,11 +142,14 @@ func (s *NotificationService) CreateAndSendNotification(ctx context.Context, use
 		err = s.pushClient.SendToAll(ctx, iosTokens, androidTokens, title, body, pushData)
 		if err != nil {
 			s.notificationRepo.SetError(notification.ID, err.Error())
-			return err
+			return apperrors.Internal(err)
 		}
 	}
 
-	return s.notificationRepo.MarkAsSent(notification.ID)
+	if err := s.notificationRepo.MarkAsSent(notification.ID); err != nil {
+		return apperrors.Internal(err)
+	}
+	return nil
 }
 
 // isNotificationEnabled checks if a notification type is enabled for user
@@ -161,7 +178,7 @@ func (s *NotificationService) isNotificationEnabled(prefs *models.NotificationPr
 func (s *NotificationService) GetPreferences(userID uint) (*NotificationPreferencesResponse, error) {
 	prefs, err := s.notificationRepo.GetOrCreatePreferences(userID)
 	if err != nil {
-		return nil, err
+		return nil, apperrors.Internal(err)
 	}
 	return NewNotificationPreferencesResponse(prefs), nil
 }
@@ -170,7 +187,7 @@ func (s *NotificationService) GetPreferences(userID uint) (*NotificationPreferen
 func (s *NotificationService) UpdatePreferences(userID uint, req *UpdatePreferencesRequest) (*NotificationPreferencesResponse, error) {
 	prefs, err := s.notificationRepo.GetOrCreatePreferences(userID)
 	if err != nil {
-		return nil, err
+		return nil, apperrors.Internal(err)
 	}
 
 	if req.TaskDueSoon != nil {
@@ -214,7 +231,7 @@ func (s *NotificationService) UpdatePreferences(userID uint, req *UpdatePreferen
 	}
 
 	if err := s.notificationRepo.UpdatePreferences(prefs); err != nil {
-		return nil, err
+		return nil, apperrors.Internal(err)
 	}
 
 	return NewNotificationPreferencesResponse(prefs), nil
@@ -230,7 +247,7 @@ func (s *NotificationService) RegisterDevice(userID uint, req *RegisterDeviceReq
 	case push.PlatformAndroid:
 		return s.registerGCMDevice(userID, req)
 	default:
-		return nil, ErrInvalidPlatform
+		return nil, apperrors.BadRequest("error.invalid_platform")
 	}
 }
 
@@ -244,7 +261,7 @@ func (s *NotificationService) registerAPNSDevice(userID uint, req *RegisterDevic
 		existing.Name = req.Name
 		existing.DeviceID = req.DeviceID
 		if err := s.notificationRepo.UpdateAPNSDevice(existing); err != nil {
-			return nil, err
+			return nil, apperrors.Internal(err)
 		}
 		return NewAPNSDeviceResponse(existing), nil
 	}
@@ -258,7 +275,7 @@ func (s *NotificationService) registerAPNSDevice(userID uint, req *RegisterDevic
 		Active:         true,
 	}
 	if err := s.notificationRepo.CreateAPNSDevice(device); err != nil {
-		return nil, err
+		return nil, apperrors.Internal(err)
 	}
 	return NewAPNSDeviceResponse(device), nil
 }
@@ -273,7 +290,7 @@ func (s *NotificationService) registerGCMDevice(userID uint, req *RegisterDevice
 		existing.Name = req.Name
 		existing.DeviceID = req.DeviceID
 		if err := s.notificationRepo.UpdateGCMDevice(existing); err != nil {
-			return nil, err
+			return nil, apperrors.Internal(err)
 		}
 		return NewGCMDeviceResponse(existing), nil
 	}
@@ -288,7 +305,7 @@ func (s *NotificationService) registerGCMDevice(userID uint, req *RegisterDevice
 		Active:           true,
 	}
 	if err := s.notificationRepo.CreateGCMDevice(device); err != nil {
-		return nil, err
+		return nil, apperrors.Internal(err)
 	}
 	return NewGCMDeviceResponse(device), nil
 }
@@ -297,12 +314,12 @@ func (s *NotificationService) registerGCMDevice(userID uint, req *RegisterDevice
 func (s *NotificationService) ListDevices(userID uint) ([]DeviceResponse, error) {
 	iosDevices, err := s.notificationRepo.FindAPNSDevicesByUser(userID)
 	if err != nil && !errors.Is(err, gorm.ErrRecordNotFound) {
-		return nil, err
+		return nil, apperrors.Internal(err)
 	}
 
 	androidDevices, err := s.notificationRepo.FindGCMDevicesByUser(userID)
 	if err != nil && !errors.Is(err, gorm.ErrRecordNotFound) {
-		return nil, err
+		return nil, apperrors.Internal(err)
 	}
 
 	result := make([]DeviceResponse, 0, len(iosDevices)+len(androidDevices))
@@ -317,14 +334,19 @@ func (s *NotificationService) ListDevices(userID uint) ([]DeviceResponse, error)
 
 // DeleteDevice deletes a device
 func (s *NotificationService) DeleteDevice(deviceID uint, platform string, userID uint) error {
+	var err error
 	switch platform {
 	case push.PlatformIOS:
-		return s.notificationRepo.DeactivateAPNSDevice(deviceID)
+		err = s.notificationRepo.DeactivateAPNSDevice(deviceID)
 	case push.PlatformAndroid:
-		return s.notificationRepo.DeactivateGCMDevice(deviceID)
+		err = s.notificationRepo.DeactivateGCMDevice(deviceID)
 	default:
-		return ErrInvalidPlatform
+		return apperrors.BadRequest("error.invalid_platform")
 	}
+	if err != nil {
+		return apperrors.Internal(err)
+	}
+	return nil
 }
 
 // === Response/Request Types ===
@@ -490,7 +512,7 @@ func (s *NotificationService) CreateAndSendTaskNotification(
 	// Check user notification preferences
 	prefs, err := s.notificationRepo.GetOrCreatePreferences(userID)
 	if err != nil {
-		return err
+		return apperrors.Internal(err)
 	}
 	if !s.isNotificationEnabled(prefs, notificationType) {
 		return nil // Skip silently
@@ -527,13 +549,13 @@ func (s *NotificationService) CreateAndSendTaskNotification(
 	}
 
 	if err := s.notificationRepo.Create(notification); err != nil {
-		return err
+		return apperrors.Internal(err)
 	}
 
 	// Get device tokens
 	iosTokens, androidTokens, err := s.notificationRepo.GetActiveTokensForUser(userID)
 	if err != nil {
-		return err
+		return apperrors.Internal(err)
 	}
 
 	// Convert data for push payload
@@ -556,9 +578,12 @@ func (s *NotificationService) CreateAndSendTaskNotification(
 		err = s.pushClient.SendActionableNotification(ctx, iosTokens, androidTokens, title, body, pushData, iosCategoryID)
 		if err != nil {
 			s.notificationRepo.SetError(notification.ID, err.Error())
-			return err
+			return apperrors.Internal(err)
 		}
 	}
 
-	return s.notificationRepo.MarkAsSent(notification.ID)
+	if err := s.notificationRepo.MarkAsSent(notification.ID); err != nil {
+		return apperrors.Internal(err)
+	}
+	return nil
 }