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/Baseline/BaselineLoader.cs

@@ -0,0 +1,88 @@
+using System.Globalization;
+
+namespace StellaOps.Bench.ScannerAnalyzers.Baseline;
+
+internal static class BaselineLoader
+{
+    public static async Task<IReadOnlyDictionary<string, BaselineEntry>> LoadAsync(string path, CancellationToken cancellationToken)
+    {
+        if (string.IsNullOrWhiteSpace(path))
+        {
+            throw new ArgumentException("Baseline path must be provided.", nameof(path));
+        }
+
+        var resolved = Path.GetFullPath(path);
+        if (!File.Exists(resolved))
+        {
+            throw new FileNotFoundException($"Baseline file not found at {resolved}", resolved);
+        }
+
+        var result = new Dictionary<string, BaselineEntry>(StringComparer.OrdinalIgnoreCase);
+
+        await using var stream = new FileStream(resolved, FileMode.Open, FileAccess.Read, FileShare.Read);
+        using var reader = new StreamReader(stream);
+        string? line;
+        var isFirst = true;
+
+        while ((line = await reader.ReadLineAsync().ConfigureAwait(false)) is not null)
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+            if (string.IsNullOrWhiteSpace(line))
+            {
+                continue;
+            }
+
+            if (isFirst)
+            {
+                isFirst = false;
+                if (line.StartsWith("scenario,", StringComparison.OrdinalIgnoreCase))
+                {
+                    continue;
+                }
+            }
+
+            var entry = ParseLine(line);
+            result[entry.ScenarioId] = entry;
+        }
+
+        return result;
+    }
+
+    private static BaselineEntry ParseLine(string line)
+    {
+        var parts = line.Split(',', StringSplitOptions.TrimEntries);
+        if (parts.Length < 6)
+        {
+            throw new InvalidDataException($"Baseline CSV row malformed: '{line}'");
+        }
+
+        var scenarioId = parts[0];
+        var iterations = ParseInt(parts[1], nameof(BaselineEntry.Iterations));
+        var sampleCount = ParseInt(parts[2], nameof(BaselineEntry.SampleCount));
+        var meanMs = ParseDouble(parts[3], nameof(BaselineEntry.MeanMs));
+        var p95Ms = ParseDouble(parts[4], nameof(BaselineEntry.P95Ms));
+        var maxMs = ParseDouble(parts[5], nameof(BaselineEntry.MaxMs));
+
+        return new BaselineEntry(scenarioId, iterations, sampleCount, meanMs, p95Ms, maxMs);
+    }
+
+    private static int ParseInt(string value, string field)
+    {
+        if (!int.TryParse(value, NumberStyles.Integer, CultureInfo.InvariantCulture, out var parsed))
+        {
+            throw new InvalidDataException($"Failed to parse integer {field} from '{value}'.");
+        }
+
+        return parsed;
+    }
+
+    private static double ParseDouble(string value, string field)
+    {
+        if (!double.TryParse(value, NumberStyles.Float, CultureInfo.InvariantCulture, out var parsed))
+        {
+            throw new InvalidDataException($"Failed to parse double {field} from '{value}'.");
+        }
+
+        return parsed;
+    }
+}