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 public trial, ranking audit, or scholarship cut puts the protagonist one failure away from losing everything". It should also strengthen the lane promise behind "mech". Enforcer or the system around them should hit back harder by the end.