Add impact index fixture and filesystem artifact uploader

- Introduced a sample BOM index JSON file for impact index testing.
- Created unit tests for the impact index fixture to ensure proper loading of sample images.
- Implemented the FilesystemPackRunArtifactUploader class to handle artifact uploads to the local filesystem.
- Added comprehensive tests for the FilesystemPackRunArtifactUploader, covering file copying, missing files, and expression outputs.

src/Scheduler/__Tests/StellaOps.Scheduler.WebService.Tests/SchedulerWebApplicationFactory.cs

@@ -1,11 +1,14 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Mvc.Testing;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
 using StellaOps.Scheduler.WebService.Options;
 using StellaOps.Scheduler.WebService.Runs;
+using StellaOps.Scheduler.ImpactIndex;
 
 namespace StellaOps.Scheduler.WebService.Tests;
 
@@ -15,6 +18,8 @@ public sealed class SchedulerWebApplicationFactory : WebApplicationFactory<Progr
     {
         builder.ConfigureAppConfiguration((_, configuration) =>
         {
+            var fixtureDirectory = GetFixtureDirectory();
+
             configuration.AddInMemoryCollection(new[]
             {
                 new KeyValuePair<string, string?>("Scheduler:Authority:Enabled", "false"),
@@ -27,12 +32,22 @@ public sealed class SchedulerWebApplicationFactory : WebApplicationFactory<Progr
                 new KeyValuePair<string, string?>("Scheduler:Events:Webhooks:Excitor:Enabled", "true"),
                 new KeyValuePair<string, string?>("Scheduler:Events:Webhooks:Excitor:HmacSecret", "excitor-secret"),
                 new KeyValuePair<string, string?>("Scheduler:Events:Webhooks:Excitor:RateLimitRequests", "20"),
-                new KeyValuePair<string, string?>("Scheduler:Events:Webhooks:Excitor:RateLimitWindowSeconds", "60")
+                new KeyValuePair<string, string?>("Scheduler:Events:Webhooks:Excitor:RateLimitWindowSeconds", "60"),
+                new KeyValuePair<string, string?>("Scheduler:ImpactIndex:FixtureDirectory", fixtureDirectory)
             });
         });
 
         builder.ConfigureServices(services =>
         {
+            var fixtureDirectory = GetFixtureDirectory();
+
+            services.RemoveAll<ImpactIndexStubOptions>();
+            services.AddSingleton(new ImpactIndexStubOptions
+            {
+                FixtureDirectory = fixtureDirectory,
+                SnapshotId = "tests/impact-index-stub"
+            });
+
             services.Configure<SchedulerEventsOptions>(options =>
             {
                 options.Webhooks ??= new SchedulerInboundWebhooksOptions();
@@ -52,4 +67,14 @@ public sealed class SchedulerWebApplicationFactory : WebApplicationFactory<Progr
             });
         });
     }
+
+    private static string GetFixtureDirectory()
+    {
+        var assemblyLocation = typeof(SchedulerWebApplicationFactory).Assembly.Location;
+        var assemblyDirectory = Path.GetDirectoryName(assemblyLocation)
+            ?? AppContext.BaseDirectory;
+
+        var fixtureDirectory = Path.Combine(assemblyDirectory, "seed-data", "impact-index");
+        return Path.GetFullPath(fixtureDirectory);
+    }
 }