Exports withSecurityHeaders() and getNonce() from the
./security/tanstack subpath. withSecurityHeaders() returns all six
security headers plus x-nonce for use inside a TanStack/Nitro H3
server middleware; getNonce() reads x-nonce from the node request
headers forwarded by that middleware.
Mirrors the ./security/next adapter pattern while staying free of
any @tanstack/start dependency — the adapter works with plain H3
IncomingMessage types that TanStack Start exposes at wiring time
(Story 09).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>