feat: Add initial implementation of Vulnerability Resolver Jobs

- Created project for StellaOps.Scanner.Analyzers.Native.Tests with necessary dependencies.
- Documented roles and guidelines in AGENTS.md for Scheduler module.
- Implemented IResolverJobService interface and InMemoryResolverJobService for handling resolver jobs.
- Added ResolverBacklogNotifier and ResolverBacklogService for monitoring job metrics.
- Developed API endpoints for managing resolver jobs and retrieving metrics.
- Defined models for resolver job requests and responses.
- Integrated dependency injection for resolver job services.
- Implemented ImpactIndexSnapshot for persisting impact index data.
- Introduced SignalsScoringOptions for configurable scoring weights in reachability scoring.
- Added unit tests for ReachabilityScoringService and RuntimeFactsIngestionService.
- Created dotnet-filter.sh script to handle command-line arguments for dotnet.
- Established nuget-prime project for managing package downloads.

src/Findings/StellaOps.Findings.Ledger.Tests/Observability/LedgerMetricsTests.cs

@@ -0,0 +1,63 @@
+using System.Diagnostics.Metrics;
+using System.Linq;
+using FluentAssertions;
+using StellaOps.Findings.Ledger.Observability;
+using Xunit;
+
+namespace StellaOps.Findings.Ledger.Tests.Observability;
+
+public class LedgerMetricsTests
+{
+    [Fact]
+    public void RecordProjectionApply_emits_histogram_and_counter_with_tags()
+    {
+        var histogramValues = new List<Measurement<double>>();
+        var counterValues = new List<Measurement<long>>();
+
+        using var listener = new MeterListener
+        {
+            InstrumentPublished = (instrument, l) =>
+            {
+                if (instrument.Meter.Name == "StellaOps.Findings.Ledger")
+                {
+                    l.EnableMeasurementEvents(instrument);
+                }
+            }
+        };
+
+        listener.SetMeasurementEventCallback<double>((instrument, measurement, _) =>
+        {
+            if (instrument.Name is "ledger_projection_apply_seconds" or "ledger_projection_lag_seconds")
+            {
+                histogramValues.Add(measurement);
+            }
+        });
+
+        listener.SetMeasurementEventCallback<long>((instrument, measurement, _) =>
+        {
+            if (instrument.Name == "ledger_projection_events_total")
+            {
+                counterValues.Add(measurement);
+            }
+        });
+
+        listener.Start();
+
+        LedgerMetrics.RecordProjectionApply(
+            TimeSpan.FromMilliseconds(40),
+            1.2,
+            "tenant-x",
+            "finding.status.changed",
+            "v1.0",
+            "affected");
+
+        histogramValues.Should().NotBeEmpty();
+        counterValues.Should().NotBeEmpty();
+
+        var tags = histogramValues.First().Tags.ToDictionary(kv => kv.Key, kv => kv.Value?.ToString());
+        tags["tenant"].Should().Be("tenant-x");
+        tags["event_type"].Should().Be("finding.status.changed");
+        tags["policy_version"].Should().Be("v1.0");
+        tags["evaluation_status"].Should().Be("affected");
+    }
+}