Suppress rare-event 0.5 unders (juiced, no-edge) — config-driven grade + board fix

Betting-logic audit: the CONSENSUS-vs-MODEL board flooded with fake reads like
"DOUBLES u0.5 · MODEL 0.2 · +edge" — the juiced under side of rare counting-stat
markets (doubles/triples/HR/SB), which is never a takeable edge and violates the
no-unders-default doctrine.

Report finding (item 3/4): the doubles projection is REAL per-player, not a flat
fallback — 'doubles' maps to a real game-log field (MLB_LOG_FIELD doubles→
doubles) and the live values varied (0.03/0.16/0.2/0.22). So no projection-gate
refusal for fakeness; the problem is purely structural (a rare event's real
projection always sits below a 0.5 line, so the under always "wins").

Fix (config-driven — src/config/rareEventMarkets.js, tunable stat list + line
threshold):
- Grade layer (analyzeViaEngine1): a rare-event UNDER at ≤0.5 is always REFUSED
  (grade null + suppressed flag/reason). A rare-event OVER at ≤0.5 is refused
  UNLESS the model genuinely projects the event above the line — because a
  0.2-over-0.5 carries the SAME |edge| as the suppressed under and would just
  take its rank on the board. The over grades normally once projection > line.
- Board layer (marketBreadth.collectBreadth): drops null-model rows so a
  suppressed/ungraded prop can't rank a "MODEL —" placeholder onto the board.

10 suppression tests + config locks; also fixed a settingsPage book assertion
left over from the ESPN→theScore swap. Suite 274/3289 green, web build exit 0.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/src/lib/marketBreadth.js

@@ -104,6 +104,11 @@ function collectBreadth(items, limit = 6) {
     if (!it) continue;
     const b = computeBreadth(it.books, it.modelValue, it.side);
     if (!b) continue;
+    // Betting-logic audit — a CONSENSUS-vs-MODEL row needs a model opinion. A
+    // prop with no model (ungraded, or a refused/suppressed read like a
+    // rare-event 0.5 market) has nothing to compare — drop it, don't rank a
+    // "MODEL —" placeholder onto the board.
+    if (b.model == null || b.signedEdge == null) continue;
     out.push({ player: it.player, stat: it.stat, line: numOrNull(it.line), ...b });
   }
   const abs = (x) => Math.abs(numOrNull(x) == null ? 0 : numOrNull(x));