Add task completion notification trigger

When a task is completed, send push notifications to all residence
users (except the person who completed it). Uses the existing
NotificationService.CreateAndSendNotification method.

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

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

internal/services/task_service.go

@@ -1,9 +1,12 @@
 package services
 
 import (
+	"context"
 	"errors"
+	"fmt"
 	"time"
 
+	"github.com/rs/zerolog/log"
 	"gorm.io/gorm"
 
 	"github.com/treytartt/mycrib-api/internal/dto/requests"
@@ -23,8 +26,9 @@ var (
 
 // TaskService handles task business logic
 type TaskService struct {
-	taskRepo      *repositories.TaskRepository
-	residenceRepo *repositories.ResidenceRepository
+	taskRepo            *repositories.TaskRepository
+	residenceRepo       *repositories.ResidenceRepository
+	notificationService *NotificationService
 }
 
 // NewTaskService creates a new task service
@@ -35,6 +39,11 @@ func NewTaskService(taskRepo *repositories.TaskRepository, residenceRepo *reposi
 	}
 }
 
+// SetNotificationService sets the notification service (for breaking circular dependency)
+func (s *TaskService) SetNotificationService(ns *NotificationService) {
+	s.notificationService = ns
+}
+
 // === Task CRUD ===
 
 // GetTask gets a task by ID with access check
@@ -461,16 +470,69 @@ func (s *TaskService) CreateCompletion(req *requests.CreateTaskCompletionRequest
 		return nil, err
 	}
 
-	// Reload
+	// Reload completion with user info
 	completion, err = s.taskRepo.FindCompletionByID(completion.ID)
 	if err != nil {
 		return nil, err
 	}
 
+	// Send notification to residence owner and other users
+	s.sendTaskCompletedNotification(task, completion)
+
 	resp := responses.NewTaskCompletionResponse(completion)
 	return &resp, nil
 }
 
+// sendTaskCompletedNotification sends notifications when a task is completed
+func (s *TaskService) sendTaskCompletedNotification(task *models.Task, completion *models.TaskCompletion) {
+	if s.notificationService == nil {
+		log.Debug().Msg("Notification service not configured, skipping task completion notification")
+		return
+	}
+
+	// Get all users with access to this residence
+	users, err := s.residenceRepo.GetResidenceUsers(task.ResidenceID)
+	if err != nil {
+		log.Error().Err(err).Uint("task_id", task.ID).Msg("Failed to get residence users for notification")
+		return
+	}
+
+	completedByName := "Someone"
+	if completion.CompletedBy.ID > 0 {
+		completedByName = completion.CompletedBy.GetFullName()
+	}
+
+	title := "Task Completed"
+	body := fmt.Sprintf("%s completed: %s", completedByName, task.Title)
+
+	data := map[string]interface{}{
+		"task_id":       task.ID,
+		"residence_id":  task.ResidenceID,
+		"completion_id": completion.ID,
+	}
+
+	// Notify all users except the one who completed the task
+	for _, user := range users {
+		if user.ID == completion.CompletedByID {
+			continue // Don't notify the person who completed it
+		}
+
+		go func(userID uint) {
+			ctx := context.Background()
+			if err := s.notificationService.CreateAndSendNotification(
+				ctx,
+				userID,
+				models.NotificationTaskCompleted,
+				title,
+				body,
+				data,
+			); err != nil {
+				log.Error().Err(err).Uint("user_id", userID).Uint("task_id", task.ID).Msg("Failed to send task completion notification")
+			}
+		}(user.ID)
+	}
+}
+
 // GetCompletion gets a task completion by ID
 func (s *TaskService) GetCompletion(completionID, userID uint) (*responses.TaskCompletionResponse, error) {
 	completion, err := s.taskRepo.FindCompletionByID(completionID)