Module errors 

Error type constants for metrics and logging.

These constants provide consistent error classification across all crates.

Constants

ERROR_AUTH

Authentication error.

ERROR_CONFIG

Configuration error.

ERROR_IO

I/O error.

ERROR_PROTOCOL

Protocol parsing/validation error.

ERROR_RESOLVE

DNS/address resolution error.

ERROR_TIMEOUT

Timeout error.

ERROR_TLS_HANDSHAKE

TLS handshake error.