feat: Implement vulnerability token signing and verification utilities

- Added VulnTokenSigner for signing JWT tokens with specified algorithms and keys.
- Introduced VulnTokenUtilities for resolving tenant and subject claims, and sanitizing context dictionaries.
- Created VulnTokenVerificationUtilities for parsing tokens, verifying signatures, and deserializing payloads.
- Developed VulnWorkflowAntiForgeryTokenIssuer for issuing anti-forgery tokens with configurable options.
- Implemented VulnWorkflowAntiForgeryTokenVerifier for verifying anti-forgery tokens and validating payloads.
- Added AuthorityVulnerabilityExplorerOptions to manage configuration for vulnerability explorer features.
- Included tests for FilesystemPackRunDispatcher to ensure proper job handling under egress policy restrictions.

docs/benchmarks/scanner/README.md

@@ -0,0 +1,26 @@
+# Scanner Benchmarks & Coverage Dossiers
+
+This directory aggregates competitive analyses, deep dives, and demand signals that inform the Scanner roadmap.
+
+## Structure
+- `../../scanner-feature-comparison-*.md` — high-level feature comparisons versus Trivy, Grype, Snyk.
+- `deep-dives/` — ecosystem-specific implementation deep dives (languages, OS packages, secrets, macOS, Windows, etc.).
+- `scanning-gaps-stella-misses-from-competitors.md` — gap analysis with scorecards, implementation plans, and backlog references.
+- `windows-macos-demand.md` — demand tracker and next actions for Windows/macOS coverage.
+- `windows-macos-interview-template.md` — structured questionnaire for customer discovery.
+
+## Quick links
+- macOS: `deep-dives/macos.md`, `../../modules/scanner/design/macos-analyzer.md`.
+- Windows: `deep-dives/windows.md`, `../../modules/scanner/design/windows-analyzer.md`.
+- Policy readiness: `../../modules/policy/secret-leak-detection-readiness.md`, `../../modules/policy/windows-package-readiness.md`.
+- API dashboards: `../../api/scanner/windows-coverage.md`, `../../api/scanner/windows-macos-summary.md`.
+
+## Maintenance tips
+- When new interview signals are logged, update `windows-macos-demand.md`, the API dashboards, and cross-link relevant design docs.
+- Ensure gap scorecards reflect the latest findings and backlog IDs.
+- Keep feature comparison docs aligned with deep dive updates.
+
+## Backlog references
+- Engineering: see `../../modules/scanner/TASKS.md` (SCANNER-ENG-0020..0027).
+- Docs: `../../docs/TASKS.md` (DOCS-SCANNER-BENCH-62-016).
+- Policy: `../../modules/policy/TASKS.md` (POLICY-READINESS-0001/0002).