C8/C6: certified planar near cluster coefficients alpha_1, alpha_2 = nu(2) and the elder-failure constant C_fail^{B,K} in [0.0027244, 0.0027312] (about 1.5e5 below the cap route), for the reference kernel and the torus model with every L >= 10 (v1.2); conditional d = 3 corollary; scientific effect NONE - #217