docs: adversarial accuracy pass + world-class README rewrite

- Reconcile eval-coverage counts to canonical 19 measured / 20 unmeasured
  (fix SYNTHESIS §7.1 CEILING 8->7 map-territory double-count, UNMEASURED 19->20;
   EVAL-COVERAGE + FUTURE-CONSOLIDATION-PLAN stale 17/22 superseded notes)
- Correct ACTIVE-PULL McNemar split (14 discordant = 11 skill-wins to 3 placebo-wins, net +5.3pp)
- Add missing [SUPERSEDED] tag to EVALUATION run1 claim; align SCORECARD MD date to JSON
- Collapse redundant doubled [SUPERSEDED] markers (provenance tuples preserved)
- Fix broken nested code fence in CONTRIBUTING
- Rewrite README for SEO/GEO/AEO: definition-first opener, TL;DR box, FAQ,
  honest zero-robust-ELEVATE framing, all 39 skills + evidence links preserved