rebrand: PropDataGuard → DataPointer

- App name: PropDataGuard → DataPointer
- Frontend title: 财险数据分级分类平台 → 数据分类分级管理平台
- LocalStorage keys: pdg_token/pdg_refresh → dp_token/dp_refresh
- Package name: prop-data-guard-frontend → data-pointer-frontend
- Project config: admin@propdataguard.com → admin@datapo.com
- Celery app name: prop_data_guard → data_pointer
- Layout logo, login title, page title all updated

backend/app/tasks/worker.py

@@ -2,7 +2,7 @@ from celery import Celery
 from app.core.config import settings
 
 celery_app = Celery(
-    "prop_data_guard",
+    "data_pointer",
     broker=settings.REDIS_URL,
     backend=settings.REDIS_URL,
     include=["app.tasks.classification_tasks"],