Tweak runner dificulty

I was thinking if we could add something like "jump strenght paramíters"/"double jumping" then add double height boxes. we could also,counter Max jumping spam by tighteing box distances spawn

The issue names no files, tests, or entry points, so first locate the runner jump logic and box-spawn logic. Clarify whether jump-strength parameters, double jumping, double-height boxes, and wider spawn distances are all required. Done should include agreed behavior for each change and a way to verify that jump spam is limited.

Written by the indexing model from the issue text.