v0.29.0

Marketing & presentation surface: routekit.dev landing SPA (packages/marketing-site, dark-mode + ux287 blue) and four presentation decks (what-is-rks, how-rks-works, rks-for-product-and-design, building-a-product-knowledge-graph). Backlog: logged build-path/off-rail hardening items (refine-noop escalation, sync-hooks off-rail wedge, on-rail non-core builds). Marketing content is publish-excluded and does not ship to the public repo.