Fix #1244: Avoid unnecessary code blocks in switch case sections

Only wrap switch case statements in a Block when a local variable
declaration is present. Otherwise emit statements directly, eliminating
the extra level of braces and indentation.

https://claude.ai/code/session_01AkwUvu3XuCdj3D4axoX4UX

Author: claude

CodeConverter/CSharp/MethodBodyExecutableStatementVisitor.cs

@@ -885,7 +885,10 @@ public override async Task<SyntaxList<StatementSyntax>> VisitSelectBlock(VBSynta
             if (!DefinitelyExits(csBlockStatements.LastOrDefault())) {
                 csBlockStatements.Add(SyntaxFactory.BreakStatement());
             }
-            var list = SingleStatement(SyntaxFactory.Block(csBlockStatements));
+            var hasLocalDeclaration = csBlockStatements.Any(s => s.IsKind(SyntaxKind.LocalDeclarationStatement));
+            var list = hasLocalDeclaration
+                ? SingleStatement(SyntaxFactory.Block(csBlockStatements))
+                : SyntaxFactory.List(csBlockStatements);
             sections.Add(SyntaxFactory.SwitchSection(SyntaxFactory.List(labels), list));
         }