Land the v0.1 editor integration: the git_sync module (libgit2 on the SD /sd/repo, dedicated 96KB git thread, lazy Wi-Fi, :sync push with synced/up-to-date/failed snackbars), the boot splash (Spike 9) plus its bin and justfile recipes, and a power-on→cursor boot-timing log. Also re-syncs the roadmap/spikes/v0.1-product status and adds the SD hardware reference photo.