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/Authority/StellaOps.Authority/StellaOps.Auth.Abstractions/StellaOpsScopes.cs

@@ -206,8 +206,29 @@ public static class StellaOpsScopes
     /// <summary>
     /// Scope granting read-only access to Vuln Explorer resources and permalinks.
     /// </summary>
+    [Obsolete("Use vuln:view (StellaOpsScopes.VulnView) instead.")]
     public const string VulnRead = "vuln:read";
 
+    /// <summary>
+    /// Scope granting read-only access to Vuln Explorer findings, reports, and dashboards.
+    /// </summary>
+    public const string VulnView = "vuln:view";
+
+    /// <summary>
+    /// Scope permitting triage actions (assign, comment, annotate) within Vuln Explorer.
+    /// </summary>
+    public const string VulnInvestigate = "vuln:investigate";
+
+    /// <summary>
+    /// Scope permitting state-changing operations (status transitions, remediation workflows) within Vuln Explorer.
+    /// </summary>
+    public const string VulnOperate = "vuln:operate";
+
+    /// <summary>
+    /// Scope permitting access to Vuln Explorer audit exports and immutable ledgers.
+    /// </summary>
+    public const string VulnAudit = "vuln:audit";
+
     /// <summary>
     /// Scope granting read-only access to observability dashboards and overlays.
     /// </summary>
@@ -399,7 +420,13 @@ public static class StellaOpsScopes
         FindingsRead,
         EffectiveWrite,
         GraphRead,
+        VulnView,
+        VulnInvestigate,
+        VulnOperate,
+        VulnAudit,
+#pragma warning disable CS0618 // track removal once legacy scope dropped
         VulnRead,
+#pragma warning restore CS0618
         ObservabilityRead,
         TimelineRead,
         TimelineWrite,