feat: Add RustFS artifact object store and migration tool

- Implemented RustFsArtifactObjectStore for managing artifacts in RustFS.
- Added unit tests for RustFsArtifactObjectStore functionality.
- Created a RustFS migrator tool to transfer objects from S3 to RustFS.
- Introduced policy preview and report models for API integration.
- Added fixtures and tests for policy preview and report functionality.
- Included necessary metadata and scripts for cache_pkg package.

bench/Scanner.Analyzers/StellaOps.Bench.ScannerAnalyzers/Reporting/BenchmarkScenarioReport.cs

@@ -0,0 +1,55 @@
+using StellaOps.Bench.ScannerAnalyzers.Baseline;
+
+namespace StellaOps.Bench.ScannerAnalyzers.Reporting;
+
+internal sealed class BenchmarkScenarioReport
+{
+    private const double RegressionLimitDefault = 1.2d;
+
+    public BenchmarkScenarioReport(ScenarioResult result, BaselineEntry? baseline, double? regressionLimit = null)
+    {
+        Result = result ?? throw new ArgumentNullException(nameof(result));
+        Baseline = baseline;
+        RegressionLimit = regressionLimit is { } limit && limit > 0 ? limit : RegressionLimitDefault;
+        MaxRegressionRatio = CalculateRatio(result.MaxMs, baseline?.MaxMs);
+        MeanRegressionRatio = CalculateRatio(result.MeanMs, baseline?.MeanMs);
+    }
+
+    public ScenarioResult Result { get; }
+
+    public BaselineEntry? Baseline { get; }
+
+    public double RegressionLimit { get; }
+
+    public double? MaxRegressionRatio { get; }
+
+    public double? MeanRegressionRatio { get; }
+
+    public bool RegressionBreached => MaxRegressionRatio.HasValue && MaxRegressionRatio.Value >= RegressionLimit;
+
+    public string? BuildRegressionFailureMessage()
+    {
+        if (!RegressionBreached || MaxRegressionRatio is null)
+        {
+            return null;
+        }
+
+        var percentage = (MaxRegressionRatio.Value - 1d) * 100d;
+        return $"{Result.Id} exceeded regression budget: max {Result.MaxMs:F2} ms vs baseline {Baseline!.MaxMs:F2} ms (+{percentage:F1}%)";
+    }
+
+    private static double? CalculateRatio(double current, double? baseline)
+    {
+        if (!baseline.HasValue)
+        {
+            return null;
+        }
+
+        if (baseline.Value <= 0d)
+        {
+            return null;
+        }
+
+        return current / baseline.Value;
+    }
+}