Add multi-factor conviction gate to activation

Make "qualified" mean an edge candidate, not just R:R + confidence.
The gate now also requires (all admin-configurable, defaults on):
- high conviction: recommended_action LONG_HIGH / SHORT_HIGH only
- clean read: risk_level Low (no contradicting signals)
- probable primary target: best target probability >= min (default 60)

- Shared predicate: app/services/qualification.py +
  frontend/src/lib/qualification.ts (mirrored)
- Activation config extended (min_target_probability,
  require_high_conviction, exclude_conflicts) with bool-aware
  get/update + validation
- /trades/performance switched to ?qualified_only=true, applying
  the full gate server-side; confidence breakdown stays unfiltered
- Dashboard "Qualified", Signals "Qualified only" toggle, and
  Track Record all use the one gate; Admin gains the new controls

Sentiment provider runtime config (prior change) included.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/src/hooks/useAdmin.ts

@@ -126,13 +126,13 @@ export function useUpdateActivationSettings() {
   const { addToast } = useToast();
 
   return useMutation({
-    mutationFn: (payload: Record<string, number>) =>
+    mutationFn: (payload: Partial<import('../lib/types').ActivationConfig>) =>
       adminApi.updateActivationSettings(payload),
     onSuccess: () => {
       qc.invalidateQueries({ queryKey: ['admin', 'activation-settings'] });
       qc.invalidateQueries({ queryKey: ['activation'] });
       qc.invalidateQueries({ queryKey: ['performance'] });
-      addToast('success', 'Activation thresholds updated');
+      addToast('success', 'Activation gate updated');
     },
     onError: (error: Error) => {
       addToast('error', error.message || 'Failed to update activation thresholds');
@@ -140,6 +140,41 @@ export function useUpdateActivationSettings() {
   });
 }
 
+export function useSentimentSettings() {
+  return useQuery({
+    queryKey: ['admin', 'sentiment-settings'],
+    queryFn: () => adminApi.getSentimentSettings(),
+  });
+}
+
+export function useUpdateSentimentSettings() {
+  const qc = useQueryClient();
+  const { addToast } = useToast();
+
+  return useMutation({
+    mutationFn: (payload: { provider?: string; model?: string; api_key?: string }) =>
+      adminApi.updateSentimentSettings(payload),
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ['admin', 'sentiment-settings'] });
+      addToast('success', 'Sentiment provider updated');
+    },
+    onError: (error: Error) => {
+      addToast('error', error.message || 'Failed to update sentiment provider');
+    },
+  });
+}
+
+export function useTestSentimentProvider() {
+  const { addToast } = useToast();
+
+  return useMutation({
+    mutationFn: (ticker: string) => adminApi.testSentimentSettings(ticker),
+    onError: (error: Error) => {
+      addToast('error', error.message || 'Sentiment test failed');
+    },
+  });
+}
+
 export function useTickerUniverseSetting() {
   return useQuery({
     queryKey: ['admin', 'ticker-universe'],