feat: Add Scanner CI runner and related artifacts

- Implemented `run-scanner-ci.sh` to build and run tests for the Scanner solution with a warmed NuGet cache.
- Created `excititor-vex-traces.json` dashboard for monitoring Excititor VEX observations.
- Added Docker Compose configuration for the OTLP span sink in `docker-compose.spansink.yml`.
- Configured OpenTelemetry collector in `otel-spansink.yaml` to receive and process traces.
- Developed `run-spansink.sh` script to run the OTLP span sink for Excititor traces.
- Introduced `FileSystemRiskBundleObjectStore` for storing risk bundle artifacts in the filesystem.
- Built `RiskBundleBuilder` for creating risk bundles with associated metadata and providers.
- Established `RiskBundleJob` to execute the risk bundle creation and storage process.
- Defined models for risk bundle inputs, entries, and manifests in `RiskBundleModels.cs`.
- Implemented signing functionality for risk bundle manifests with `HmacRiskBundleManifestSigner`.
- Created unit tests for `RiskBundleBuilder`, `RiskBundleJob`, and signing functionality to ensure correctness.
- Added filesystem artifact reader tests to validate manifest parsing and artifact listing.
- Included test manifests for egress scenarios in the task runner tests.
- Developed timeline query service tests to verify tenant and event ID handling.

ops/devops/signals/dashboards/excititor-vex-traces.json

@@ -0,0 +1,50 @@
+{
+  "title": "Excititor VEX Observations Traces",
+  "tags": ["excititor", "traces", "vex"],
+  "timezone": "browser",
+  "schemaVersion": 38,
+  "version": 1,
+  "refresh": "30s",
+  "panels": [
+    {
+      "type": "stat",
+      "title": "Spans (last 15m)",
+      "gridPos": {"h": 4, "w": 6, "x": 0, "y": 0},
+      "targets": [
+        {
+          "refId": "A",
+          "datasource": {"type": "tempo", "uid": "tempo"},
+          "expr": "sum by(service_name)(rate(traces_spanmetrics_calls_total{service_name=~\"excititor.*\"}[15m]))"
+        }
+      ]
+    },
+    {
+      "type": "stat",
+      "title": "Errors (last 15m)",
+      "gridPos": {"h": 4, "w": 6, "x": 6, "y": 0},
+      "targets": [
+        {
+          "refId": "A",
+          "datasource": {"type": "tempo", "uid": "tempo"},
+          "expr": "sum by(status_code)(rate(traces_spanmetrics_calls_total{status_code=\"STATUS_CODE_ERROR\",service_name=~\"excititor.*\"}[15m]))"
+        }
+      ]
+    },
+    {
+      "type": "table",
+      "title": "Recent /v1/vex/observations spans",
+      "gridPos": {"h": 12, "w": 24, "x": 0, "y": 4},
+      "options": {
+        "showHeader": true
+      },
+      "targets": [
+        {
+          "refId": "A",
+          "datasource": {"type": "tempo", "uid": "tempo"},
+          "queryType": "traceql",
+          "expr": "{ service.name = \"excititor\" && http.target = \"/v1/vex/observations\" } | limit 50"
+        }
+      ]
+    }
+  ]
+}