Fix variant pricing: resolve reverse prices from *-holo fields, hide unpriced rows

TCGdex publishes reverse-holo prices in avg-holo when a card has no holo
variant (e.g. swsh2-83: reverse=true, holo=false, avg-reverse absent).
Variant rows are now shown only when a real price exists, and collection
pricing resolves Reverse via avg-reverse ?? avg-holo ?? avg.

src/lib/collection.ts

@@ -35,7 +35,15 @@ export async function priceCollectionCards(
             const cardmarket = detail?.pricing?.cardmarket;
             if (cardmarket) {
                 const priceKey = variantPriceMap[card.variant ?? ""] ?? "avg";
-                price = cardmarket[priceKey] ?? cardmarket.avg ?? 0;
+                // TCGdex quirk: reverse prices may live in the *-holo
+                // fields when the card has no holo variant
+                price =
+                    cardmarket[priceKey] ??
+                    (card.variant === "Reverse"
+                        ? cardmarket["avg-holo"]
+                        : undefined) ??
+                    cardmarket.avg ??
+                    0;
             }
             return { ...card, price, totalPrice: price };
         }),

src/pages/card/[id].astro

@@ -53,16 +53,30 @@ const availableVariants = card.variants
 
 const variantPrices: { label: string; price: number }[] = [];
 
-// Always include the base avg price (0 when no Cardmarket data)
-variantPrices.push({ label: "Base", price: cardmarket?.avg ?? 0 });
+// TCGdex quirk: when a card has a reverse variant but no holo variant,
+// the reverse price is published in the *-holo fields (avg-reverse absent)
+const priceKeyFor = (variant: string): string => {
+    if (variant === "reverse" && card.variants?.holo === false) {
+        return cardmarket?.["avg-reverse"] != null
+            ? "avg-reverse"
+            : "avg-holo";
+    }
+    return variantPriceMap[variant];
+};
 
-// Add prices for each available variant
+// Base price row, only when actually priced
+if (cardmarket?.avg != null) {
+    variantPrices.push({ label: "Base", price: cardmarket.avg });
+}
+
+// Variant rows, only when the price actually exists
 for (const variant of availableVariants) {
     if (variant === "normal") continue; // normal uses the base avg, already added
-    const priceKey = variantPriceMap[variant];
-    const price = cardmarket?.[priceKey] ?? 0;
+    const price = cardmarket?.[priceKeyFor(variant)];
+    if (price != null) {
         variantPrices.push({ label: variantLabels[variant] ?? variant, price });
     }
+}
 
 // Determine which tabs have content
 const hasAttacks = card.attacks && card.attacks.length > 0;