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/__Libraries/StellaOps.Scheduler.ImpactIndex/Fixtures/sample.bom-index.json

@@ -0,0 +1,23 @@
+{
+  "schema": "scheduler-impact-index@1",
+  "generatedAt": "2025-10-01T00:00:00Z",
+  "image": {
+    "repository": "registry.stellaops.test/team/sample-service",
+    "digest": "sha256:0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef",
+    "tag": "1.0.0"
+  },
+  "components": [
+    {
+      "purl": "pkg:docker/sample-service@1.0.0",
+      "usage": [
+        "runtime"
+      ]
+    },
+    {
+      "purl": "pkg:pypi/requests@2.31.0",
+      "usage": [
+        "usedByEntrypoint"
+      ]
+    }
+  ]
+}

src/Scheduler/__Libraries/StellaOps.Scheduler.ImpactIndex/StellaOps.Scheduler.ImpactIndex.csproj

@@ -8,6 +8,7 @@
     <ProjectReference Include="../StellaOps.Scheduler.Models/StellaOps.Scheduler.Models.csproj" />
   </ItemGroup>
   <ItemGroup>
+    <EmbeddedResource Include="Fixtures\**\*.json" />
     <EmbeddedResource Include="..\..\samples\scanner\images\**\bom-index.json"
                       Link="Fixtures\%(RecursiveDir)%(Filename)%(Extension)" />
   </ItemGroup>