On Pro: an active "WAStore Pro" badge and a "Manage on Stripe" button
(Stripe's own portal — update payment method, view invoices, cancel).
On Free: an upgrade card with a Monthly/Yearly toggle, a "Compare Free
& Pro" link to the pricing page, the full list of what Pro unlocks, an
"Upgrade to Pro" button (Stripe checkout), and — if unused — a "Try Pro
free for 7 days" button (no card required, one trial per account ever).
If a renewal payment fails (expired card, not enough funds, bank
declined): the store drops to Free immediately. There is no grace
period. Pro/Max features lock as described in "Free vs Pro", and nothing
is deleted. WAStore emails the owner right away with the reason and a link
to pay the open invoice, plus reminders on day 3 and day 7 while it's
unpaid; Stripe may also send its own email. Once that invoice is paid
(through the link, or with a new card), the plan comes back.
If an upgrade payment fails (the first checkout didn't go through):
the store stays on Free. WAStore emails the owner about a day later with
the reason and a link to try again, and once more 3 days after that.