feat: Enhance MongoDB storage with event publishing and outbox support

- Added `MongoAdvisoryObservationEventPublisher` and `NatsAdvisoryObservationEventPublisher` for event publishing.
- Registered `IAdvisoryObservationEventPublisher` to choose between NATS and MongoDB based on configuration.
- Introduced `MongoAdvisoryObservationEventOutbox` for outbox pattern implementation.
- Updated service collection to include new event publishers and outbox.
- Added a new hosted service `AdvisoryObservationTransportWorker` for processing events.

feat: Update project dependencies

- Added `NATS.Client.Core` package to the project for NATS integration.

test: Add unit tests for AdvisoryLinkset normalization

- Created `AdvisoryLinksetNormalizationConfidenceTests` to validate confidence score calculations.

fix: Adjust confidence assertion in `AdvisoryObservationAggregationTests`

- Updated confidence assertion to allow a range instead of a fixed value.

test: Implement tests for AdvisoryObservationEventFactory

- Added `AdvisoryObservationEventFactoryTests` to ensure correct mapping and hashing of observation events.

chore: Configure test project for Findings Ledger

- Created `Directory.Build.props` for test project configuration.
- Added `StellaOps.Findings.Ledger.Exports.Unit.csproj` for unit tests related to findings ledger exports.

feat: Implement export contracts for findings ledger

- Defined export request and response contracts in `ExportContracts.cs`.
- Created various export item records for findings, VEX, advisories, and SBOMs.

feat: Add export functionality to Findings Ledger Web Service

- Implemented endpoints for exporting findings, VEX, advisories, and SBOMs.
- Integrated `ExportQueryService` for handling export logic and pagination.

test: Add tests for Node language analyzer phase 22

- Implemented `NodePhase22SampleLoaderTests` to validate loading of NDJSON fixtures.
- Created sample NDJSON file for testing.

chore: Set up isolated test environment for Node tests

- Added `node-isolated.runsettings` for isolated test execution.
- Created `node-tests-isolated.sh` script for running tests in isolation.

src/Scanner/__Tests/node-tests-isolated.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+set -euo pipefail
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# repo root = two levels up from src/Scanner (__Tests/.. -> .. -> ..)
+REPO_ROOT="$(cd "$SCRIPT_DIR/../../.." && pwd)"
+cd "$REPO_ROOT"
+
+# Restore only filtered projects using offline/local feed
+NUGET_PACKAGES="$REPO_ROOT/offline/packages" \
+DOTNET_RESTORE_DISABLE_PARALLEL=true \
+DOTNET_SYSTEM_NET_HTTP_USESOCKETSHTTPHANDLER=0 \
+dotnet restore src/Scanner/StellaOps.Scanner.Node.slnf \
+  -p:RestorePackagesPath="$REPO_ROOT/offline/packages" \
+  -p:ContinuousIntegrationBuild=true
+
+# Run node analyzer tests in isolation
+DOTNET_SYSTEM_GLOBALIZATION_INVARIANT=1 \
+DOTNET_CLI_TELEMETRY_OPTOUT=1 \
+dotnet test src/Scanner/StellaOps.Scanner.Node.slnf \
+  --no-build \
+  --settings "$REPO_ROOT/__Tests/node-isolated.runsettings" \
+  /m:1