Add FORMA static storefront, Shopify theme & Ruby adapter, integration hooks and CI checks

[feispla]

Motivation

• Provide a self-contained, static-first FORMA storefront demo with safe runtime integration hooks for Shopify, Supabase and Chatbase while keeping secrets out of git.
• Add a Shopify Liquid theme scaffold and a small Ruby adapter for server-side Admin API tasks to enable future upstreamable work.
• Enable reproducible verification and an agent-friendly workflow (issue template, PR template, docs) and enforce a preflight npm run check via GitHub Actions.

Description

• Add a complete static storefront (index.html) plus assets: assets/store.js, assets/integrations.js, assets/store.css and demo assets/config.js to run locally in demo mode.
• Add integration and ops docs (docs/INTEGRATIONS.md, docs/GO_LIVE_CHECKLIST.md, CLAUDE.md, docs/GITHUB_PLAIN_DIFFS.md) and GitHub templates (.github/ISSUE_TEMPLATE/ai-agent-task.md, .github/pull_request_template.md).
• Add a Shopify theme scaffold under shopify-theme/ with templates, snippets, assets and RSpec-style structure tests, plus a Ruby adapter under shopify-ruby/ with AdminClient, StorefrontClient, shopify_context and a smoke script.
• Add tooling and verification scripts: scripts/smoke-static.js, scripts/verify-files.js, scripts/github-plain-diff.js, scripts/prepare-shopify-upstream.sh, and scripts/list_products.rb for the Ruby adapter.
• Add package.json with dev, start and a composite check script that runs npm run verify:files, npm run smoke:static, node --check on key JS files and the theme spec, plus a package-lock.json change.
• Add CI workflow .github/workflows/check.yml that runs npm ci and npm run check on pull_request and pushes to common branches, plus vercel.json and a Supabase migration supabase/migrations/202605130001_storefront_core.sql.

Testing

• No automated tests were executed as part of this change; CI is configured to run npm run check on PRs and pushes via .github/workflows/check.yml.
• The repository now includes the verification and smoke-check scripts (scripts/verify-files.js, scripts/smoke-static.js) and a Ruby theme spec scaffold (shopify-theme/spec/theme_structure_spec.rb) that npm run check will invoke when run in CI or locally.

---

Codex Task