Cascade Backstop — the two-tails fork

A fragile structure rarely has one future. This operator makes the fork explicit: let the loop complete, or absorb it and watch where the absorbed flow lands. Which tail materialises is stated as conditions on the three containment gates — never as a probability.

How it reads

mode_a terminal amplification vs mode_b landing decomposition; gates carries the documented deployed/sized/affordable assessment. Read with dissipation (circ_frac decides how targeted a backstop can be).