The First Test
Protagonist is pushed into a sharper version of the book's central pressure. Expose the deficit and the first practical test. The protagonist must act, not merely train or brood. It should visibly deliver on the promise of "a mech trial, salvage lottery, or combat-frame recall leaves the protagonist with one dangerous chance to jump tiers". It should also strengthen the lane promise behind "academy". Enforcer or the system around them should hit back harder by the end.