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.

src/Notifier/StellaOps.Notifier/TASKS.md

@@ -1,5 +1,10 @@
 # Notifier Service Task Board — Epic 11: Notifications Studio
 
+# Sprint 70 – Documentation & Decisions
+| ID | Status | Owner(s) | Depends on | Description | Exit Criteria |
+|----|--------|----------|------------|-------------|---------------|
+| NOTIFY-DOC-70-001 | DONE | Notifications Service Guild | — | Document the decision to keep `src/Notify` as the shared library toolkit and `src/Notifier` as the runtime host; update notifications docs with rationale and cross-links (completed 2025-11-02). | Notes published in notifications architecture docs clarifying module boundaries and citing decision. |
+
 # Sprint 37 – Pack Approval Bridge (Task Runner integration)
 | ID | Status | Owner(s) | Depends on | Description | Exit Criteria |
 |----|--------|----------|------------|-------------|---------------|