feat(legal): add privacy, terms, and cookie policy pages (#28)
Static legal pages required for GDPR compliance per decisions/legal.md.
Privacy policy covers data collection, GDPR rights, and breach notification.
Terms of service covers eligibility (16+), content rules, AI summaries, and labels.
Cookie policy documents the single HTTP-only refresh token cookie.
Footer updated to include cookies link alongside existing privacy and terms links.
authored by