add screen to view a barcode isolated

src/views.rs

@@ -1434,6 +1434,7 @@ pub fn rewards_page(user: &User, cards: &[RewardsCard], csrf_token: &str) -> Mar
                         div class="rewards-grid" {
                             @for card in cards {
                                 div class="rewards-card" {
+                                    a class="rewards-card-link" href=(format!("/rewards/{}", card.id)) aria-label=(format!("Show {} barcode", card.store_name)) {}
                                     div class="rewards-card-heading" {
                                         strong { (card.store_name) }
                                         form method="post" action=(format!("/rewards/{}/delete", card.id)) hx-confirm="Remove this rewards card? This cannot be undone." {
@@ -1471,6 +1472,29 @@ pub fn rewards_page(user: &User, cards: &[RewardsCard], csrf_token: &str) -> Mar
     )
 }
 
+/// A focused, single-barcode view for scanning at the register. Only one
+/// barcode is shown at a time so a scanner can't pick up multiple codes.
+pub fn rewards_scan_page(user: &User, card: &RewardsCard) -> Markup {
+    page(
+        &card.store_name,
+        Some(user),
+        html! {
+            div class="scan-page" {
+                a class="button button-quiet scan-back" href="/rewards" { "← All cards" }
+                div class="scan-card" {
+                    p class="eyebrow" { "REWARDS CARD" }
+                    h1 class="scan-store" { (card.store_name) }
+                    div class="scan-barcode" {
+                        (barcode_svg(&card.symbology, &card.number))
+                    }
+                    p class="rewards-number" { (card.number) }
+                }
+            }
+            script src=(crate::assets::url("rewards.js")) {}
+        },
+    )
+}
+
 /// Renders a rewards-card number as an inline SVG barcode using the given
 /// symbology. Falls back to a plain text label if the number can't be encoded
 /// (for example, a Code 128 number that isn't valid for the chosen symbology).