feat: Phase 4 — Moteur Probabiliste & Apprentissage Automatique

Sprint 4.1 — Bayesian Updating
- database.py: update_bayesian_posteriors() — Beta(α,β) posteriors sur trades matures
- database.py: get_bayesian_posteriors() — posteriors + IC 95% + dérive prior GPT vs posterior
- Colonnes Bayésiennes ajoutées : bayesian_alpha, bayesian_beta, bayesian_win_rate, bayesian_sample_size
- auto_cycle.py: appel update_bayesian_posteriors() en Step 5.5 (après scoring)

Sprint 4.2 — Détection Automatique de Régimes (K-Means numpy pur)
- database.py: detect_and_save_regime_clusters() — K-Means sur 7 gauges macro (VIX, slope, DXY…)
- database.py: get_regime_cluster_history() — timeline des clusters
- database.py: get_regime_transition_matrix() — P(cluster j | cluster i) sur N transitions
- Table regime_clusters avec anomaly_flag (points > 3σ)
- auto_cycle.py: appel detect_and_save_regime_clusters() en Step 5.6

Sprint 4.3 — Embeddings Sémantiques (remplace Jaccard)
- database.py: get_or_create_pattern_embedding() — OpenAI text-embedding-3-small, stocké en DB
- database.py: max_cosine_similarity_vs_existing() — similarité cosinus vs patterns existants
- Table pattern_embeddings avec vecteur JSON + model_version
- auto_cycle.py: _is_duplicate_pattern() — cosinus seuil 0.75 avec fallback Jaccard automatique

Sprint 4.4 — Tableau de Bord Analytique Avancé
- AnalyticsAdvanced.tsx: nouvelle page /analytics-advanced
  • BayesianTable : prior GPT vs WR bayésien ± IC 95%, dérive, niveau de confiance
  • ClusterTimeline : timeline colorée des clusters + anomalies
  • TransitionMatrix : heatmap P(j|i) avec diagonale auto-transition
  • EmbeddingsSummary : liste des patterns vectorisés
  • Boutons "Bayesian update" et "Détecter régime" avec mutation React Query
- analytics.py router : 5 nouveaux endpoints (bayesian, regime-clusters, transitions, detect, embeddings)
- useApi.ts : 4 nouveaux hooks (useBayesianPosteriors, useRegimeClusters, useRegimeTransitions, usePatternEmbeddings)
- App.tsx + Sidebar.tsx : route /analytics-advanced + entrée menu

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/hooks/useApi.ts

@@ -614,6 +614,36 @@ export const useIvForTrade = (underlying: string) =>
     staleTime: 60 * 60_000,
   })
 
+// ── Analytics Phase 4 — Bayesian + Clustering + Embeddings ───────────────────
+
+export const useBayesianPosteriors = () =>
+  useQuery({
+    queryKey: ['bayesian-posteriors'],
+    queryFn: () => api.get('/analytics/bayesian').then(r => r.data),
+    staleTime: 5 * 60_000,
+  })
+
+export const useRegimeClusters = (days = 90) =>
+  useQuery({
+    queryKey: ['regime-clusters', days],
+    queryFn: () => api.get('/analytics/regime-clusters', { params: { days } }).then(r => r.data),
+    staleTime: 5 * 60_000,
+  })
+
+export const useRegimeTransitions = (days = 180) =>
+  useQuery({
+    queryKey: ['regime-transitions', days],
+    queryFn: () => api.get('/analytics/regime-transitions', { params: { days } }).then(r => r.data),
+    staleTime: 10 * 60_000,
+  })
+
+export const usePatternEmbeddings = () =>
+  useQuery({
+    queryKey: ['pattern-embeddings'],
+    queryFn: () => api.get('/analytics/embeddings').then(r => r.data),
+    staleTime: 10 * 60_000,
+  })
+
 // ── Analytics (Phase 2) ───────────────────────────────────────────────────────
 
 export const usePatternReliability = () =>