Portfolio: privacy, terms and age requirement before launch #48

Part of #40. Depends on #41.

Scope

• Privacy page: what portfolio data is stored, who can see it, the search visibility setting, and how to delete it.
• Terms of Use: acceptable use for public pages (no impersonation, phishing, or copyrighted material) and how pages are taken down.
• Age requirement for publishing, as decided in the ADR, with a confirmation step in the editor.

The owner must review and approve all legal wording. Do not publish placeholder legal text.

Done when

The pages are updated, the owner has approved the wording, and npm run launch-check passes.