Recurring subscriptions and Zaprite payments — the two v0.3
features the section advertised as upcoming — both shipped in the
v0.2 line and gate on the recurring_billing / card_payments
entitlements as planned. Section copy was stale and confusing.
The left sidebar already covers Install / Integrate / Wire format /
Operate across its four groups (Get started, Concepts, Reference,
Operate). The top-right nav duplicated those links one level up. On
mobile it was already hidden via @media rule, so the sidebar was
always the canonical navigation. Now it's the only navigation —
cleaner topbar, no duplication.
Standard docs-site convention: top-left brand goes to the marketing
home, the 'Docs' badge next to it signals you're in the docs section.
The separate 'Marketing' nav item is no longer needed once the brand
itself handles that link.