Adds a prominent Keep it free sponsor button to the top nav, linking to https://github.com/sponsors/snapotter-hq. Solid orange pill on desktop (left of the avatar), orange heart icon on mobile. Opens in a new tab with rel=noopener noreferrer, so no referrer or user data leaks, and it adds no passive network activity (offline-mode compatible). Fires an opt-in, property-less sponsor_clicked analytics event. Adds sidebar.sponsor and a11y.sponsorLink across all 21 locales.
Claude-Session: https://claude.ai/code/session_01DnYLLA5z4Uf1GDeEPENVgr
