feat: Implement Runtime Facts ingestion service and NDJSON reader

- Added RuntimeFactsNdjsonReader for reading NDJSON formatted runtime facts.
- Introduced IRuntimeFactsIngestionService interface and its implementation.
- Enhanced Program.cs to register new services and endpoints for runtime facts.
- Updated CallgraphIngestionService to include CAS URI in stored artifacts.
- Created RuntimeFactsValidationException for validation errors during ingestion.
- Added tests for RuntimeFactsIngestionService and RuntimeFactsNdjsonReader.
- Implemented SignalsSealedModeMonitor for compliance checks in sealed mode.
- Updated project dependencies for testing utilities.

src/Scanner/__Tests/StellaOps.Scanner.Analyzers.Lang.Tests/Lang/Ruby/RubyLanguageAnalyzerTests.cs

@@ -1,3 +1,4 @@
+using StellaOps.Scanner.Analyzers.Lang;
 using StellaOps.Scanner.Analyzers.Lang.Ruby;
 using StellaOps.Scanner.Analyzers.Lang.Tests.Harness;
 using StellaOps.Scanner.Analyzers.Lang.Tests.TestUtilities;
@@ -11,10 +12,13 @@ public sealed class RubyLanguageAnalyzerTests
     {
         var fixture = TestPaths.ResolveFixture("lang", "ruby", "basic");
         var golden = Path.Combine(fixture, "expected.json");
+        var usageHints = new LanguageUsageHints(new[] { Path.Combine(fixture, "app", "main.rb") });
+
         await LanguageAnalyzerTestHarness.AssertDeterministicAsync(
             fixture,
             golden,
             new ILanguageAnalyzer[] { new RubyLanguageAnalyzer() },
-            cancellationToken: TestContext.Current.CancellationToken);
+            cancellationToken: TestContext.Current.CancellationToken,
+            usageHints: usageHints);
     }
 }