Resolves issue #1870, hardens auth context helpers so unauthenticated requests cannot use unvalidated requester header context for identity or role decisions.

[david-rocca]

Closes Issue #1870

Summary

This change distinguishes between requests where authentication has not been evaluated and requests where authentication was evaluated and failed. Once authentication has failed, auth-context helpers no longer fall back to raw req.ctx.org or req.ctx.user values when resolving requester organization, requester user, UUIDs, Secretariat status, bulk-download status, admin status, or admin-of-org status.

Important Changes

src/middleware/middleware.js

• Added req.ctx.authenticationChecked.
• Set the flag in both required and optional authentication middleware after auth evaluation succeeds or fails.

src/utils/authContext.js

• Added a helper for detecting unauthenticated requests after an auth check.
• Prevented raw requester header fallback for unauthenticated-after-check requests.
• Preserved trusted UUID-based internal context behavior.

test/unit-tests/utils/authContextTest.js

• Added unit coverage for unauthenticated fallback blocking.
• Added coverage for trusted internal UUID context and authenticated UUID context.

test/integration-tests/cve-id/getCveIdTest.js

• Added an integration regression for invalid credentials on an optionally authenticated endpoint.