b6d0fe4706
- invoices.rs: arm_grin1_rail issues a native Grin invoice slate for every exact-amount invoice at create time (off the async workers; best-effort) and stores its armored I1 + slate id. - checkout.rs: build_info surfaces the invoice slatepack (primary Grin method) and gates the plain-send address panel behind the render gate. - pay.html: reworked into a CSS-only two-rail switcher — 'Pay with Goblin' (nprofile) and 'Pay with any Grin wallet' (invoice slatepack primary, plain-send address only when the gate allows). Zero-JS meta-refresh + wordmark header + dark theme preserved; plain QRs; no em dashes. - style.css: rail switcher styles (hidden radios + :checked sibling combinator).