feat(insights): anomaly outcome validator — hit-rate calibration page

Adds a calibration dashboard that joins persisted SuspensionFlip anomalies
with EventResult rows and reports whether the post-flip favourite actually
won — the single metric that says whether the detector is doing its job.

Domain:
- AnomalyEvidenceData + AnomalyEvidenceParser to read the JSON written by
  AnomalyDetector without re-implementing the schema.
- AnomalyOutcomeEvaluator: pure function returning Hit / Miss / Unresolved.
  Tennis-style two-way markets with a Draw winner are downgraded to
  Unresolved rather than silently counted as Miss.
- AnomalySeverityThresholds: shared Low/Medium/High constants so the UI
  badge and the report buckets cannot drift.

Application:
- EvaluateAnomalyOutcomesUseCase orchestrates the join + aggregation.
- AnomalyOutcomeReport carries totals, hit rate, three breakdowns
  (severity / sport / score bins) and a per-event title lookup so the UI
  needs no second pass over IEventRepository.
- Score bins extend below 0.30 automatically when the operator lowers the
  detector threshold so the histogram total always equals ResolvedCount.

UI:
- Insights page at /anomalies/insights — hero header, 4-card KPI strip
  (hit rate tinted by tone), three breakdown grids with bar visualisation,
  drill-down tables for resolved and unresolved anomalies. Honors
  prefers-reduced-motion. RU + EN localisation.
- Nav entry under Analysis section + chip button on the Anomaly Feed.

Tests: +42 across Domain + Application (evaluator boundary cases including
tennis two-way and Draw guard, score-bin edges, dynamic floor when
threshold is lowered, event-title pass-through). All 324 tests pass.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/Marathon.UI/Services/AnomalyViewModels.cs

@@ -1,3 +1,4 @@
+using Marathon.Domain.AnomalyDetection;
 using Marathon.Domain.Enums;
 using Marathon.Domain.ValueObjects;
 
@@ -83,12 +84,14 @@ public enum AnomalyFavourite
     None,
 }
 
-/// <summary>Helpers for severity bucketing.</summary>
+/// <summary>Helpers for severity bucketing. Thresholds come from
+/// <see cref="AnomalySeverityThresholds"/> so the UI badges and the
+/// Application-layer outcome report agree by construction.</summary>
 public static class AnomalySeverityRules
 {
-    public const decimal LowThreshold = 0.30m;
-    public const decimal MediumThreshold = 0.45m;
-    public const decimal HighThreshold = 0.60m;
+    public const decimal LowThreshold = AnomalySeverityThresholds.Low;
+    public const decimal MediumThreshold = AnomalySeverityThresholds.Medium;
+    public const decimal HighThreshold = AnomalySeverityThresholds.High;
 
     public static AnomalySeverity FromScore(decimal score) => score switch
     {