Combine 10 screen recordings into one video

We have screen recordings covering 10 slides, shared as Google Drive links. We need them joined into one continuous video in the order we give.

Download the files, trim dead air at the start and end of each clip, even out audio levels, use consistent transitions (a simple cut or cross-dissolve, your choice), match resolution and frame rate, and deliver an MP4 (1080p, H.264) plus an upload to our shared Drive folder.