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>

src/Recordingtest.SutProber/Program.cs

@@ -28,6 +28,7 @@ var assemblies = AssemblyScanner.Scan(sutPath);
 var opts = new JsonSerializerOptions
 {
     WriteIndented = true,
+    PropertyNamingPolicy = JsonNamingPolicy.SnakeCaseLower,
     // deterministic property order follows POCO definition
 };