Numerical acceptance policy

The implementation first checks identity, constant, dephasing, and the flagged even benchmark against analytical optima. For every new channel it records:

• raw recovery variables and affine/positivity residuals;

• a positive trace-preserving decoder obtained by explicit Choi normalization;

• an independent fixed-channel diamond primal and dual;

• a fidelity-dual lower-bound candidate;

• solver settings, statuses, and computed gaps.

Numerical positivity checks and scalar repairs are not interval certificates. Values remain numerical estimates unless stronger verification is supplied. An optimizer's status string alone is insufficient.