RenderLog.engine

RenderLog.engine names the rendering engine used for the call. Today the service renders with pdf-lib, so every row carries the literal string pdf-lib. The field exists so the log stays meaningful if a second engine is ever introduced: historical rows would still attribute their output to the engine that produced it, and operators could compare latency or size between engines. For now it is a constant, but it is recorded on every render — success or failure.