Main configuration d=256, L=64: all data, figures and checks re-run

Every OMA reference takes the L/16 combining gain so the comparison
stays resource matched, four hardcoded copies of the configuration are
replaced by MAIN_D or the main curve, and stage_J's K-by-L Gaussian
draw becomes its exact scalar Beta equivalent.

data/sec_sens.csv

@@ -1,23 +1,23 @@
 rho,eve_ser
-0,0.999985
-0.1,0.99994625
-0.2,0.9998125
-0.3,0.99964375
-0.4,0.99860875
-0.5,0.99641875
-0.6,0.989405
-0.65,0.9817575
-0.7,0.96633
-0.75,0.9402875
-0.8,0.87396
-0.84,0.80818
-0.88,0.7000025
-0.9,0.62012
-0.92,0.51693625
-0.94,0.4271675
-0.96,0.3636825
-0.97,0.33119875
-0.98,0.30263125
-0.99,0.2772575
-0.995,0.26772625
-1,0.25672125
+0,0.9999725
+0.1,0.999645
+0.2,0.9978275
+0.3,0.98789125
+0.4,0.953745
+0.5,0.846655
+0.6,0.60245875
+0.65,0.48618375
+0.7,0.32927
+0.75,0.23272375
+0.8,0.1458875
+0.84,0.1059525
+0.88,0.08334375
+0.9,0.07761625
+0.92,0.069835
+0.94,0.06505125
+0.96,0.0602775
+0.97,0.0587575
+0.98,0.05626875
+0.99,0.0543425
+0.995,0.054125
+1,0.05307125