Optional certificate QR, multi-product access grants, and sold-out prices handled cleanly

Second release of the day, after the morning batch.

🎓 Certificates

• New Verification QR is optional. Certificates → Templates → a simple template → Show on certificate has a QR verification switch. Off means the printed certificate carries no QR code; the verification page and link still work for every issued certificate. Existing templates keep the QR on. In the advanced designer you can now delete the QR element as well.
• New A custom line per course, e.g. CPD hours. Course Settings has an Extra line on the certificate field, and the simple designer has an Extra line (per course) switch that places it on the template. One template can serve courses with different hours or accreditation notes.

👥 Customers & access

• Improved Grant access to several products at once. Customer page → Actions → Grant access takes one or more products. Price, end-of-access, and community-role overrides stay available when you pick a single product.
• Improved Revoke access with a checklist. Revoke access in the Actions menu lists the customer's active grants, all preselected, so you can uncheck what should stay. It replaces the old Revoke all access item in the ⋮ menu.
• New Cancel the Stripe subscription of an already-archived client. When access was revoked without canceling the billing, the revoked row on the customer's Access tab now offers Cancel subscription in Stripe. It stops future charges; it does not refund the current period. Active grants still cancel through the usual archive / change-access flow.
• Fixed Renewal links survive an e-mail change. A customer who opens a renewal link sent before you changed their e-mail can still pay, and the order lands under their current address. Failed-payment e-mails and their renewal link also go to the current address.
• Fixed Adding a customer whose login account already exists. Add customer, changing a customer's e-mail, and CSV or audience imports no longer fail with "e-mail already exists" when the person has a leftover login account from before.

🛒 Checkout & payments

• Fixed Sold-out prices are not offered. A price variant whose seat limit is reached shows as sold out and cannot be selected, including variants that went over their limit through pending orders. An attempt to order one gets a clear "price not available" answer instead of a generic payment error.
• Fixed Checkout Builder preview follows your dashboard language. When neither the checkout, the product, nor your site sets a language, the preview and the After purchase mocks use the language of your dashboard instead of always English. An explicitly set language still wins, exactly like the live checkout.
• Improved Source URL on conversion events. Analytics → Traffic & conversions → Events → open a Purchase or InitiateCheckout event to see the page address that was sent to Meta or TikTok, so you can verify URL-based rules without guessing.

🤖 Assistant & support

• Fixed The assistant stays in your language. An English conversation no longer drifts into Polish after a quick-reply chip or a one-word turn; the conversation language is pinned for replies and suggested chips alike.
• Improved The assistant knows when a price is sold out. Asked why a payment "doesn't work", it checks seat limits first and points you to the price's availability settings instead of blaming the gateway.
• Improved New request status: On our list / Confirmed. In Help Center, a feature idea we have read and queued shows On our list; a reported issue we have reproduced shows Confirmed. Replies on either side keep the status until we move it on.

🔧 Also shipped

• Improved Failed platform-payment e-mails reach both addresses. Notices about a failed payment for your Zanfia plan go to the workspace contact e-mail and your account e-mail (once, when they are the same).
• Fixed Login on a closed creator platform explains itself. A customer who tries to log in to a platform whose creator has closed their account sees "this platform is no longer available" instead of a generic "could not send the code" error.