feat: add admin apis

internal/repository/social_graph_repo.go

@@ -315,6 +315,18 @@ func (r *NotificationRepo) Create(ctx context.Context, userID string, actorID *s
 	return n, nil
 }
 
+// CreateAdminMessage persists an admin → user direct message. Unlike the
+// event-driven kinds it has no actor and carries free text in `body`.
+func (r *NotificationRepo) CreateAdminMessage(ctx context.Context, userID, body string) error {
+	if _, err := r.pg.Pool.Exec(ctx,
+		`INSERT INTO notifications (user_id, kind, body) VALUES ($1, 'admin_message', $2)`,
+		userID, body,
+	); err != nil {
+		return fmt.Errorf("create admin message notification: %w", err)
+	}
+	return nil
+}
+
 // ListByUser returns a recipient's notifications, newest first, with the
 // actor's display fields joined in for rendering (nil for system
 // notifications or since-deleted actors). Kinds the user has turned off for
@@ -325,7 +337,7 @@ func (r *NotificationRepo) ListByUser(ctx context.Context, userID string, limit,
 		SELECT n.id, n.user_id, n.actor_id, n.kind, n.post_id, n.actor_count,
 		       n.created_at, n.read_at,
 		       u.name, u.handle, u.avatar_url,
-		       pu.handle
+		       pu.handle, n.body
 		FROM notifications n
 		LEFT JOIN users u ON u.id = n.actor_id
 		LEFT JOIN posts p ON p.id = n.post_id
@@ -348,7 +360,7 @@ func (r *NotificationRepo) ListByUser(ctx context.Context, userID string, limit,
 		if err := rows.Scan(&n.ID, &n.UserID, &n.ActorID, &n.Kind, &n.PostID, &n.ActorCount,
 			&n.CreatedAt, &n.ReadAt,
 			&n.ActorName, &n.ActorHandle, &n.ActorAvatar,
-			&n.PostAuthorHandle); err != nil {
+			&n.PostAuthorHandle, &n.Body); err != nil {
 			return nil, fmt.Errorf("scan notification: %w", err)
 		}
 		out = append(out, n)