feat(anomaly): suspension-freeze detector

- Add SuspensionFreezeDetector via the IAnomalyDetector seam: a suspension gap with
  the favourite unchanged and a negligible (< threshold) price move — the mirror of
  the flip. Score = how completely the line froze. Reuses MatchWinEvidence so UI +
  evaluator handle it unchanged. 6 tests.
- Add AnomalyKind.SuspensionFreeze + localized card/detail label, SuspensionFreezeThreshold
  option, and fan it into DetectAnomaliesUseCase.

src/Marathon.UI/Pages/Anomalies/Detail.razor

@@ -105,9 +105,10 @@
 
     private string KindLabel(AnomalyKind kind) => kind switch
     {
-        AnomalyKind.SuspensionFlip => L["Anomaly.Kind.SuspensionFlip"],
-        AnomalyKind.SteamMove      => L["Anomaly.Kind.SteamMove"],
-        _                          => kind.ToString(),
+        AnomalyKind.SuspensionFlip   => L["Anomaly.Kind.SuspensionFlip"],
+        AnomalyKind.SteamMove        => L["Anomaly.Kind.SteamMove"],
+        AnomalyKind.SuspensionFreeze => L["Anomaly.Kind.SuspensionFreeze"],
+        _                            => kind.ToString(),
     };
 
     private static string FormatGap(int seconds)