PassThroughAlgorithm

Trust the source; filter nothing.

This is the posture of an app that delegates motion detection to a background-geolocation SDK: the SDK has already decided what a real movement is, so re-filtering its output would be second-guessing a black box with worse information than it had.

It is also the honest benchmark baseline. Every claim of the form "our filtering improves accuracy" is meaningless without a number for "what if we did nothing at all" — this class is that number. Keep it even if no product ever ships it.

The one thing it does do is drop exact duplicates. Duplicate delivery of the same fix is a transport artefact, not a movement, and counting one twice is a bug under any philosophy.