feat: Implement Filesystem and MongoDB provenance writers for PackRun execution context

- Added `FilesystemPackRunProvenanceWriter` to write provenance manifests to the filesystem.
- Introduced `MongoPackRunArtifactReader` to read artifacts from MongoDB.
- Created `MongoPackRunProvenanceWriter` to store provenance manifests in MongoDB.
- Developed unit tests for filesystem and MongoDB provenance writers.
- Established `ITimelineEventStore` and `ITimelineIngestionService` interfaces for timeline event handling.
- Implemented `TimelineIngestionService` to validate and persist timeline events with hashing.
- Created PostgreSQL schema and migration scripts for timeline indexing.
- Added dependency injection support for timeline indexer services.
- Developed tests for timeline ingestion and schema validation.

bench/reachability-benchmark/cases/js/unsafe-eval/src/app.js

@@ -0,0 +1,17 @@
+'use strict';
+
+// Minimal HTTP-like handler exposing an unsafe eval sink for reachability.
+// The handler is intentionally small to avoid external dependencies.
+function handleRequest(body) {
+  const code = body && body.code;
+  if (typeof code !== 'string') {
+    return { status: 400, body: 'bad request' };
+  }
+
+  // Dangerous: executes user-controlled code. The test drives this sink.
+  // eslint-disable-next-line no-eval
+  const result = eval(code);
+  return { status: 200, body: String(result) };
+}
+
+module.exports = { handleRequest };