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.Tests/BaselineLoaderTests.cs

@@ -0,0 +1,37 @@
+using System.Text;
+using StellaOps.Bench.ScannerAnalyzers.Baseline;
+using Xunit;
+
+namespace StellaOps.Bench.ScannerAnalyzers.Tests;
+
+public sealed class BaselineLoaderTests
+{
+    [Fact]
+    public async Task LoadAsync_ReadsCsvIntoDictionary()
+    {
+        var csv = """
+            scenario,iterations,sample_count,mean_ms,p95_ms,max_ms
+            node_monorepo_walk,5,4,9.4303,36.1354,45.0012
+            python_site_packages_walk,5,10,12.1000,18.2000,26.3000
+            """;
+
+        var path = await WriteTempFileAsync(csv);
+
+        var result = await BaselineLoader.LoadAsync(path, CancellationToken.None);
+
+        Assert.Equal(2, result.Count);
+        var entry = Assert.Contains("node_monorepo_walk", result);
+        Assert.Equal(5, entry.Iterations);
+        Assert.Equal(4, entry.SampleCount);
+        Assert.Equal(9.4303, entry.MeanMs, 4);
+        Assert.Equal(36.1354, entry.P95Ms, 4);
+        Assert.Equal(45.0012, entry.MaxMs, 4);
+    }
+
+    private static async Task<string> WriteTempFileAsync(string content)
+    {
+        var path = Path.Combine(Path.GetTempPath(), $"baseline-{Guid.NewGuid():N}.csv");
+        await File.WriteAllTextAsync(path, content, Encoding.UTF8);
+        return path;
+    }
+}