Caddy adds none of these on its own. Add HSTS, X-Content-Type-Options,
X-Frame-Options, Referrer-Policy and a CSP scoped to default-src
'self' plus the one external asset (Google Fonts). script-src/style-src
need 'unsafe-inline' because both SPAs rely on inline onclick handlers
and style="" attributes throughout — removing those is a separate,
larger refactor.
Validated with `caddy validate` and a live container curl check.
Adds a static regression test asserting the header directives stay
present in the Caddyfile, since nothing else in the Python suite
exercises it.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
