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/real_sec_stats.json

@@ -10,22 +10,22 @@
  "headline_runs": 4,
  "recovery": {
   "20": {
-   "legit": 0.22112422997946612,
+   "legit": 0.7507700205338809,
    "eve": 0.0,
    "insider": 0.0,
-   "oma": 0.19815195071868583
+   "oma": 0.6463039014373717
   },
   "24": {
-   "legit": 0.5395277207392197,
+   "legit": 0.8966889117043121,
    "eve": 0.0,
    "insider": 0.0,
-   "oma": 0.5160420944558521
+   "oma": 0.8390657084188912
   },
   "28": {
-   "legit": 0.7804158110882957,
+   "legit": 0.9588039014373717,
    "eve": 0.0,
    "insider": 0.0,
-   "oma": 0.7583418891170431
+   "oma": 0.9319815195071869
   }
  }
 }