feat: improve assistant knowledge import and database compatibility

.gitignore

@@ -88,6 +88,8 @@ skills/
 hermes-agent-main/
 .gitignore
 offline-backend-20260512/backend/tests/*
+# Keep the openGauss URL/dialect/schema compatibility regression coverage versioned.
+!offline-backend-20260512/backend/tests/test_gauss_database.py
 !offline-backend-20260512/backend/tests/test_llmwiki_weknora.py
 !offline-backend-20260512/backend/tests/test_health_auth_bypass.py
 # Keep formal Word OOXML and embedded-font regression coverage versioned.