Add timezone utility and current branch signal to enhance park detail functionality

history_tracking/views.py

@@ -5,6 +5,7 @@ from django.template.loader import render_to_string
 from django.contrib.auth.mixins import LoginRequiredMixin
 from django.core.exceptions import ValidationError
 from django.db import transaction
+from django.utils import timezone
 
 from .models import VersionBranch, VersionTag, ChangeSet
 from .managers import BranchManager, ChangeTracker, MergeStrategy