Deploy locked React/HTML prototype as PWA — Firebase + Vercel + custom domain (fixed scope)

# Project Brief: Simplist — Build & Deploy ## What this is A fixed-scope build job: implement the attached locked HTML/React designs as a real, installable web app (PWA), deploy it, and connect a custom domain. This is a **recreate-exactly** job, not a redesign — the visual/interaction spec is fully locked (see `README.md` in this package for full detail). Design exploration is done; this is implementation only. ## Deliverable A live, installable PWA at **simplist.app** that: - Matches the three attached HTML prototypes pixel-for-pixel across iPhone, iPad, and Mac (responsive from one codebase, not three separate builds) - Persists data via Firebase (Firestore), synced live across the client's devices - Signs the client in via passwordless magic-link email (single user, no multi-account system needed) - Installs to home screen/dock on iPhone/iPad/Mac like a native app (manifest + service worker, offline-tolerant for reads) - Is deployed on Vercel with the custom domain simplist.app connected ## Required stack (client's decisions — please follow, not open for re-litigation unless there's a strong technical reason) - Hosting: **Vercel** - Backend/sync: **Firebase / Firestore** - Auth: **Firebase magic-link email auth** - Framework: your call (React/Next.js recommended given the prototypes are React-based, but any modern framework that hits the deliverable is fine) - Domain: client owns **simplist.app**; you'll need it pointed at Vercel via DNS (client can update DNS records themselves if you provide the values — they don't have registrar access to give you) ## Source of truth - `README.md` — full written spec: screens, interactions, known-bug-fixes-already-applied (please read the "Interactions & Behavior" section closely — it documents several subtle bugs we already found and fixed in the prototype; don't reintroduce them), design tokens (colors/type/spacing), data model. - `Simplist-Desktop-standalone.html`, `Simplist-iPad-standalone.html`, `Simplist-iPhone-standalone.html` — open any directly in a browser; each is a fully interactive prototype (add/edit/delete tasks & notes, rename/delete projects/categories, drag-free CRUD, rich text notes, custom calendar, etc.) backed by localStorage. Use these as the literal reference — click through every state before implementing, not just visually skim. ## Explicitly out of scope (do not add) - No native app / App Store submission - No multi-user accounts, sharing, or collaboration - No push notifications, widgets, or share-sheet integration - No new features or visual changes beyond what's in the prototypes — flag anything you think is missing rather than adding it unprompted ## What "done" looks like - Client can visit simplist.app on iPhone, iPad, and Mac, sign in via magic link, install to home screen, and use an app that is visually and behaviorally identical to the three prototypes, with changes syncing across all three devices in real time (or near-real-time). - A brief note back to the client on: how to make future changes/who to contact, and confirmation all three device sizes were tested. ## Questions during the build The client does not code and won't be able to answer technical implementation questions — please make reasonable, standard technical decisions yourself and flag only genuine ambiguities in the attached spec (not implementation choices within your stack).