isDebugEnabled

Hint to the SDK whether preparing expensive DEBUG payloads (message fingerprinting, UTF-8 truncation on publish/signal/subscribe) is worthwhile for this logger. Return false if the downstream sink is configured at INFO or higher; the SDK will skip that work unless another attached sink still needs DEBUG payloads.

Not a delivery filter: debug is still invoked regardless. Per-record filtering is the implementation's responsibility. Overriding is a pure performance optimization.