Applied via `dotnet format analyzers --diagnostics CA1854 --severity info`. Eliminates the duplicate hash lookup in the `if (d.ContainsKey(k)) d[k]++ else d[k] = 1` pattern. The fixer rewrites the conditional to `if (d.TryGetValue(k, out var value)) d[k] = ++value;` which is semantically identical but does the lookup once. 4 files touched. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>