Stairno

What Stairno is, why there are four sites but one account, the 10-step roadmap and where it stands (step 4 done, step 5 next), the series contents and the tools that appear in it

Roadmap step 1. Pulling the colors, fonts, header, footer, theme and language switches of the hub stairno.com out into the @stairno/ui package, and checking that not a single pixel changed. Then adding the account menu to the package

Roadmap step 2. Designing the account center and shared API in four documents (project plan, SRS, SDD, test and deploy) before any code, and an experiment to check whether sign-in really works across sites on different domains. The conclusion that it is OIDC, not cookies, and why the stack was chosen

Roadmap step 3. Building sign-up, sign-in, verification mail, device management and a sign-in gateway for sites (OIDC) with TDD in an empty repo, and putting it live on Cloudflare Workers. The first-day Workers check, mail domain authentication, Korean traffic entering through LAX, the free plan CPU limit, the shared account menu and the acceptance checklist

Roadmap step 4, the build. Putting Toss Payments and PayPal behind an adapter and building one-time payments, card registration (billing keys), subscriptions with automatic renewal, refunds, webhooks, payment mail and re-downloads, in order and by rules. Why the work moved to Git Flow midway, v0.4.0 and v0.4.1