Choosing and tuning DDS QoS for a ROS 2 sensor stream

In ROS 2, you are publishing data from a 30 Hz LiDAR over a real network where some packet loss is expected. A downstream node only cares about the *latest* scan and must never block waiting for old data, while a separate logging node needs a faithful record of every scan it can get. Explain how you would configure the DDS Quality of Service (QoS) policies for these two subscribers. Be specific about the relevant QoS settings (e.g., $\textit{reliability}$, $\textit{durability}$, $\textit{history}$, $\textit{depth}$), what the trade-offs are, and what happens to communication if a publisher and subscriber have *incompatible* QoS profiles.