Added terrain-aware automaton footsteps

I made roaming automaton footsteps follow actual travel and the alternating mechanical gait. The contact timing comes from the moving actor, rather than a repeating sound loop that continues regardless of its position.

The native sound stops for paused, dead or unloaded actors and falls out of range beyond the nearby field cutoff. Ground-contact effects remain tied to the same real patrol movement.

“Mechanical contacts follow traveled distance and alternate feet, with distance-limited sound.”

The clips show a short native patrol followed by a deliberate pause to inspect the body and contact ground. The original audio is retained and technically checked, but I have not claimed a listening review or a long natural patrol encounter.