feat: add community activity feed and mentions

app/Observers/ArtworkCommentObserver.php

@@ -6,6 +6,7 @@ namespace App\Observers;
 
 use App\Models\ArtworkComment;
 use App\Services\UserStatsService;
+use App\Services\UserMentionSyncService;
 use Illuminate\Support\Facades\DB;
 
 /**
@@ -16,6 +17,7 @@ class ArtworkCommentObserver
 {
     public function __construct(
         private readonly UserStatsService $userStats,
+        private readonly UserMentionSyncService $mentionSync,
     ) {}
 
     public function created(ArtworkComment $comment): void
@@ -28,6 +30,14 @@ class ArtworkCommentObserver
         // The commenter is "active"
         $this->userStats->ensureRow($comment->user_id);
         $this->userStats->setLastActiveAt($comment->user_id);
+        $this->mentionSync->syncForComment($comment);
+    }
+
+    public function updated(ArtworkComment $comment): void
+    {
+        if ($comment->wasChanged(['content', 'raw_content', 'rendered_content', 'parent_id'])) {
+            $this->mentionSync->syncForComment($comment);
+        }
     }
 
     /** Soft delete. */
@@ -37,6 +47,8 @@ class ArtworkCommentObserver
         if ($creatorId) {
             $this->userStats->decrementCommentsReceived($creatorId);
         }
+
+        $this->mentionSync->deleteForComment((int) $comment->id);
     }
 
     /** Hard delete after soft delete — already decremented; nothing to do. */
@@ -50,6 +62,13 @@ class ArtworkCommentObserver
                 $this->userStats->decrementCommentsReceived($creatorId);
             }
         }
+
+        $this->mentionSync->deleteForComment((int) $comment->id);
+    }
+
+    public function restored(ArtworkComment $comment): void
+    {
+        $this->mentionSync->syncForComment($comment);
     }
 
     private function creatorId(int $artworkId): ?int