feat: model validation, calibration, and signal quality layer

- Migration 035: prediction_snapshots, prediction_outcomes, signal_evidence_links, model_metric_snapshots tables + SQL views
- Prediction snapshot writer with canonical evidence keys, duplicate detection, contribution scores
- Outcome evaluator across 5 horizons (1h, 6h, 1d, 7d, 30d)
- Metrics engine: ECE, Brier score, IC, Rank IC, benchmark comparison
- Attribution engine: per-source, per-catalyst, per-layer performance
- Calibration engine: Bayesian shrinkage source reliability
- Quality gate for live trading eligibility with configurable thresholds
- 7 new /api/validation/* endpoints
- Upgraded OpsModel dashboard with validation tab
- Enhanced recommendation display with calibration context
- Backtest replay validation mode
- 86 Python tests (unit + property-based), 179 frontend tests passing

frontend/src/test/mocks/handlers.ts

@@ -73,6 +73,97 @@ export const mockVariantPerfHistory = [
   { hour: '2026-04-10T11:00:00Z', invocations: 12, successes: 11, avg_duration_ms: 1300, avg_confidence: 0.82 },
 ];
 
+// Validation: Model Quality & Calibration mock data
+export const mockValidationSummary = {
+  snapshot: {
+    id: 'ms-1',
+    generated_at: '2026-04-11T12:00:00Z',
+    lookback_window: '30d',
+    horizon: '7d',
+    prediction_count: 150,
+    win_rate: 0.58,
+    directional_accuracy: 0.56,
+    information_coefficient: 0.045,
+    rank_information_coefficient: 0.038,
+    avg_return: 0.012,
+    avg_excess_return_vs_spy: 0.003,
+    avg_excess_return_vs_sector: 0.002,
+    calibration_error: 0.08,
+    brier_score: 0.21,
+    buy_win_rate: 0.61,
+    sell_win_rate: 0.54,
+    hold_win_rate: 0.50,
+    metadata: {},
+  },
+  gate_status: {
+    passed: true,
+    reason: 'all thresholds met',
+    threshold_results: [
+      { name: 'min_prediction_count', threshold: 100, actual: 150, passed: true },
+      { name: 'min_ic', threshold: 0.03, actual: 0.045, passed: true },
+      { name: 'min_win_rate', threshold: 0.53, actual: 0.58, passed: true },
+    ],
+  },
+};
+
+export const mockValidationCalibration = {
+  buckets: [
+    { bucket_low: 0.50, bucket_high: 0.60, avg_confidence: 0.55, observed_win_rate: 0.52, prediction_count: 30, miscalibrated: false },
+    { bucket_low: 0.60, bucket_high: 0.70, avg_confidence: 0.65, observed_win_rate: 0.58, prediction_count: 40, miscalibrated: false },
+    { bucket_low: 0.70, bucket_high: 0.80, avg_confidence: 0.75, observed_win_rate: 0.55, prediction_count: 35, miscalibrated: true },
+    { bucket_low: 0.80, bucket_high: 0.90, avg_confidence: 0.85, observed_win_rate: 0.70, prediction_count: 25, miscalibrated: false },
+    { bucket_low: 0.90, bucket_high: 1.00, avg_confidence: 0.95, observed_win_rate: 0.72, prediction_count: 20, miscalibrated: true },
+  ],
+  lookback: '30d',
+  horizon: '7d',
+};
+
+export const mockValidationGateStatus = {
+  gate_status: {
+    passed: false,
+    reason: 'failed: min_ic below threshold',
+    threshold_results: [
+      { name: 'min_prediction_count', threshold: 100, actual: 150, passed: true },
+      { name: 'min_ic', threshold: 0.03, actual: 0.02, passed: false },
+      { name: 'min_win_rate', threshold: 0.53, actual: 0.58, passed: true },
+    ],
+  },
+};
+
+export const mockValidationICByHorizon = {
+  horizons: [
+    { horizon: '1h', information_coefficient: 0.02, rank_information_coefficient: 0.015, prediction_count: 120, generated_at: '2026-04-11T12:00:00Z' },
+    { horizon: '7d', information_coefficient: 0.045, rank_information_coefficient: 0.038, prediction_count: 100, generated_at: '2026-04-11T12:00:00Z' },
+  ],
+  lookback: '30d',
+};
+
+export const mockValidationAttributionSources = {
+  sources: [
+    { source: 'Reuters', source_type: 'news_api', prediction_count: 50, avg_weight: 0.6, avg_contribution_score: 0.3, win_rate: 0.62, avg_future_return: 0.015, avg_excess_return_vs_spy: 0.005, information_coefficient: 0.05, duplicate_rate: 0.1 },
+  ],
+  lookback: '30d',
+  horizon: '7d',
+};
+
+export const mockValidationAttributionCatalysts = {
+  catalysts: [
+    { catalyst_type: 'earnings', prediction_count: 40, win_rate: 0.65, avg_future_return: 0.02, avg_excess_return_vs_spy: 0.008, information_coefficient: 0.06 },
+  ],
+  lookback: '30d',
+  horizon: '7d',
+};
+
+export const mockValidationAttributionLayers = {
+  layers: [
+    { layer: 'company', avg_contribution_pct: 0.55, dominant_win_rate: 0.60, dominant_ic: 0.04 },
+    { layer: 'macro', avg_contribution_pct: 0.30, dominant_win_rate: 0.52, dominant_ic: 0.02 },
+    { layer: 'competitive', avg_contribution_pct: 0.15, dominant_win_rate: 0.48, dominant_ic: null },
+  ],
+  lookback: '30d',
+  horizon: '7d',
+};
+
 export const handlers = [
   // Query API (proxied at /api/)
   http.get('/api/companies', () => HttpResponse.json(mockCompanies)),
@@ -242,4 +333,13 @@ export const handlers = [
     const body = await request.json() as Record<string, unknown>;
     return HttpResponse.json({ enabled: body.enabled, previous_enabled: true, toggled_by: 'operator' });
   }),
+
+  // Validation: Model Quality & Calibration endpoints
+  http.get('/api/validation/summary', () => HttpResponse.json(mockValidationSummary)),
+  http.get('/api/validation/calibration', () => HttpResponse.json(mockValidationCalibration)),
+  http.get('/api/validation/gate-status', () => HttpResponse.json(mockValidationGateStatus)),
+  http.get('/api/validation/ic-by-horizon', () => HttpResponse.json(mockValidationICByHorizon)),
+  http.get('/api/validation/attribution/sources', () => HttpResponse.json(mockValidationAttributionSources)),
+  http.get('/api/validation/attribution/catalysts', () => HttpResponse.json(mockValidationAttributionCatalysts)),
+  http.get('/api/validation/attribution/layers', () => HttpResponse.json(mockValidationAttributionLayers)),
 ];