Adds a Send button to the order action extension and a corresponding
"send" op to /api/orders/:orderId/invoice. Generates the invoice on
demand if missing, then sends via the configured SMTP.
The order-action / order-block UI extensions are hosted on
extensions.shopifycdn.com and call our app via fetch(). Without CORS
headers the browser blocked the response. authenticate.admin already
returns a cors helper and handles OPTIONS preflight - wrap every
Response with it.
Vite/React Router refused to bundle the client because
app/routes/app.settings.tsx imported the constant from a .server file
and used it inside the route component (not just loader/action), so it
could not be tree-shaken out.
Move the sentinel to logoCache.constants.ts, re-export from
logoCache.server.ts for backwards compatibility, and import the constant
from constants in the route while keeping the server-only functions
(deleteStoredLogo, storeUploadedLogo) imported from .server (they are
only referenced inside the action and get tree-shaken correctly).
Gerhard Scheikl