PYSEC-2026-2580 Langroid: SQLChatAgent _validate_query blocklist misses pg_read_file family enabling arbitrary file read

Summary SQLChatAgent in langroid ships a validatequery defense-in-depth layer whose DANGEROUSSQLPATTERNS regex blocklist enumerates dangerous SQL primitives by specific function name. The list misses the canonical PostgreSQL filesystem-disclosure family pgreadfile, pgstatfile, pglslogdir,...