Removes the logged-in vs logged-out page bifurcation. index.php now
always renders the public landing (tools overview, hero, trust section)
with auth-conditional nav/hero CTAs and a two-column member/register
gate shown only to unauthenticated visitors. Authenticated workbench
extracted to new dashboard.php. Adds 8 new i18n keys across all 4
languages and new CSS for auth-nav, hero CTA, two-column gate, and
register buttons.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
