Shopify App Developer — Deploy & Finish a Partially-Built Order Documents App

I'm launching a Shopify App Store app that generates invoices, packing slips, returns forms, and gift receipts as server-rendered PDFs. The hard parts are already built and tested: the order normalization engine (discounts, taxes, multi-currency, refunds), the document renderer, and a 37-test correctness suite — all passing. Your job is integration, deployment, and getting it live in the App Store. Scope of work 1. Merge the existing codebase into a fresh Shopify Remix app scaffold (instructions provided in the repo README) 2. Set up hosting (Fly.io or Railway), Postgres, Redis, S3, and the Playwright/Chromium render worker 3. Wire up OAuth, webhooks (orders/paid, orders/fulfilled, uninstall, GDPR), and Shopify managed billing with three plans 4. Test against a dev store using a provided test plan (~30 specific test orders); fix integration mismatches between our normalizer and live API payloads 5. Build the golden-file CI job: render 24 fixture PDFs, rasterize, pixel-diff against approved snapshots 6. Complete the App Store submission (listing assets provided) and handle review feedback until approved What you get from me: complete build spec, working tested core code, test plan, listing copy, fast answers. What I need from you: clean integration work, honest status updates, and no shortcuts on the test suite.