feat: 新增独立企业深度研究工作台，并接入工作流报告结构与 8BF 深色锁定

Co-authored-by: Cursor <cursoragent@cursor.com>

.gitignore

@@ -98,9 +98,11 @@ offline-backend-20260512/backend/tests/*
 !offline-backend-20260512/backend/tests/test_deep_research_event_sink.py
 !offline-backend-20260512/backend/tests/test_deep_research_executor_reliability.py
 !offline-backend-20260512/backend/tests/test_deep_research_start_job.py
-!offline-backend-20260512/backend/tests/test_summarization_human_message.py
-!offline-backend-20260512/backend/tests/test_compact_menu_overrides.py
-deploy
+!offline-backend-20260512/backend/tests/test_summarization_human_message.py
+!offline-backend-20260512/backend/tests/test_compact_menu_overrides.py
+# Independent enterprise-research persistence, HTTP and race regressions.
+!offline-backend-20260512/backend/tests/test_enterprise_research_tasks.py
+deploy
 .history
 
 # Cloned third-party repos (local only)