sut-prober snake_case JSON + scaffolding review 1회차

- SutProber JsonNamingPolicy.SnakeCaseLower (strict contract compliance)
- Regenerated docs/sut-catalog/*.json
- CoverageTests: accept both snake_case and PascalCase (resilience)
- docs/history: scaffolding review 1회차 (no removals, audit only)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/Recordingtest.Normalizer.Tests/CoverageTests.cs

@@ -63,7 +63,9 @@ public class CoverageTests
         var allFields = new HashSet<string>(StringComparer.Ordinal);
         foreach (var entry in doc.RootElement.EnumerateArray())
         {
-            if (entry.TryGetProperty("SuspectedNondeterministicFields", out var arr))
+            // Accept both snake_case (current sut-prober) and PascalCase (legacy) for resilience.
+            if (entry.TryGetProperty("suspected_nondeterministic_fields", out var arr)
+                || entry.TryGetProperty("SuspectedNondeterministicFields", out arr))
             {
                 foreach (var f in arr.EnumerateArray())
                 {