fix: align production defaults and close review parity gaps

Ship greenfield min_rr=2.0 and conf=0, read-only Structural S/R, indicator
cache invalidation, and UI/gate language that treats GTL as screening not exit.
Align strategy_rank missing-vol fallback live vs backtest, single-source
PRIMARY_TARGET_MIN_RR, expand prod parity tests, and drop dead FE clients.

frontend/src/components/admin/ActivationSettings.tsx

@@ -3,10 +3,11 @@ import type { ActivationConfig } from '../../lib/types';
 import { useActivationSettings, useUpdateActivationSettings } from '../../hooks/useAdmin';
 import { SkeletonTable } from '../ui/Skeleton';
 
+/** Mirrors app.services.admin_service.ACTIVATION_DEFAULTS — keep in sync. */
 const DEFAULTS: ActivationConfig = {
   min_momentum_percentile: 80,
-  min_rr: 1.2,
-  min_confidence: 55,
+  min_rr: 2.0,
+  min_confidence: 0,
   require_high_conviction: false,
   exclude_conflicts: false,
   exclude_neutral: true,