Color contract: 'N LIVE' count → green (Design's LIVE color), not red

Design colors every LIVE indicator green (active = green; the live-dots and
LIVE·Q3 labels are all green). The slate header's 'N LIVE' count was red
(--live #ff3b3b) — contradicts the one-meaning-per-color contract (red = miss/
error, which live isn't). Aligned to --g-a.

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

web/src/components/Slate.tsx

@@ -946,7 +946,7 @@ export default function Slate({ initialTab = 'all', tier = 'free', preferredBook
             <><span style={{ color: '#3A3A48' }}>·</span><span>{snapGrades.length} PROPS GRADED</span></>
           )}
           {games.some((g) => g.status === 'in') && (
-            <><span style={{ color: '#3A3A48' }}>·</span><span style={{ color: 'var(--live, #FF4757)', fontWeight: 700 }}>{games.filter((g) => g.status === 'in').length} LIVE</span></>
+            <><span style={{ color: '#3A3A48' }}>·</span><span style={{ color: 'var(--g-a)', fontWeight: 700 }}>{games.filter((g) => g.status === 'in').length} LIVE</span></>
           )}
           {lastRefreshed && (
             <><span style={{ color: '#3A3A48' }}>·</span><span title="The slate auto-refreshes every 60 seconds">UPDATED {freshLabel(lastRefreshed, nowTick)}</span></>