v0.29.3

Marketing site naming pass: product naming now follows the brand rules — "Routekit Shell" in the hero, header, and branding; "Routekit" in headings and callouts; "rks" reserved for body copy. Updates the Proof headline and the services callout accordingly.

First release cut with a corrected commit identity. Prior releases were authored by a stale repo-local git identity, which caused the production deploy to be blocked and left routekit.dev serving a pre-0.29.0 build; this release should restore automatic deployment of the accumulated marketing surface (UX287 logo, enlarged header lockup, self-hosted Overpass Black wordmark, Plausible analytics, Model economics pane, and the UX287 deep-dive links).