sprint: one step, finished, every session

Founders don't fail from missing strategy; they fail from open loops. Sprint closes them: every session starts oriented, works exactly one step of the roadmap to done, and ends with the state saved so tomorrow starts oriented too.

  session opens
       |
  [ standup ]   baton + active initiative -> 5 lines + ONE next move
       |
  [ gate ]      state must be planned/executing, or it routes to plan
       |
  [ one step ]  session-sized, finished completely, verified
       |
  [ close ]     box checked, fog graduated, baton rewritten