LightRAG: CORS Wildcard + Credentials Enables Any-Origin Credentialed Requests

LightRAG provides simple and fast retrieval-augmented generation. Prior to 1.5.4, the server defaults to CORS_ORIGINS=* combined with allow_credentials=True in lightrag/api/lightrag_server.py, causing Starlette CORSMiddleware to effectively whitelist every origin for credentialed cross-origin requests. Any malicious website visited by an authenticated LightRAG user can silently make authenticated API requests, exfiltrating documents and knowledge graph data or performing destructive actions such as deleting the document store. This vulnerability is fixed in 1.5.4.