Implement VEX document verification system with issuer management and signature verification

- Added IIssuerDirectory interface for managing VEX document issuers, including methods for registration, revocation, and trust validation.
- Created InMemoryIssuerDirectory class as an in-memory implementation of IIssuerDirectory for testing and single-instance deployments.
- Introduced ISignatureVerifier interface for verifying signatures on VEX documents, with support for multiple signature formats.
- Developed SignatureVerifier class as the default implementation of ISignatureVerifier, allowing extensibility for different signature formats.
- Implemented handlers for DSSE and JWS signature formats, including methods for verification and signature extraction.
- Defined various records and enums for issuer and signature metadata, enhancing the structure and clarity of the verification process.

src/Web/StellaOps.Web/tests/e2e/auth.spec.ts

@@ -1,4 +1,5 @@
-import { expect, test } from '@playwright/test';
+import { expect, test } from '@playwright/test';
+import { policyAuthorSession } from '../src/app/testing';
 
 const mockConfig = {
   authority: {
@@ -24,7 +25,7 @@ const mockConfig = {
   },
 };
 
-test.beforeEach(async ({ page }) => {
+test.beforeEach(async ({ page }) => {
   page.on('console', (message) => {
     // bubble up browser logs for debugging
     console.log('[browser]', message.type(), message.text());
@@ -32,7 +33,7 @@ test.beforeEach(async ({ page }) => {
   page.on('pageerror', (error) => {
     console.log('[pageerror]', error.message);
   });
-  await page.addInitScript(() => {
+  await page.addInitScript(() => {
     // Capture attempted redirects so the test can assert against them.
     (window as any).__stellaopsAssignedUrls = [];
     const originalAssign = window.location.assign.bind(window.location);
@@ -40,8 +41,10 @@ test.beforeEach(async ({ page }) => {
       (window as any).__stellaopsAssignedUrls.push(url.toString());
     };
 
-    window.sessionStorage.clear();
-  });
+    window.sessionStorage.clear();
+    // Seed a default Policy Studio author session so guarded routes load in e2e
+    (window as any).__stellaopsTestSession = policyAuthorSession;
+  });
   await page.route('**/config.json', (route) =>
     route.fulfill({
       status: 200,