send-gift: permitir pagar con PV (puntos de voto), más caro que PD

Solo en /send-gift se añade una 4ª forma de pago: PV (vote points, gratis por
votar). Cuesta más que PD para preservar su valor: coste_PV = coste_PD ×
VP_PRICE_FACTOR (=2, configurable en lib/pay-with-dpoints).

- lib/dpoints: getVPointsBalance, creditVPoints y spendVPoints (débito atómico
  del campo vp, con FOR UPDATE), espejo de las de PD.
- lib/pay-with-dpoints: VP_PRICE_FACTOR, vpointsCost() y payServiceWithVPoints()
  (descuenta PV, ejecuta el envío y reembolsa si falla).
- gift/checkout: rama provider='vp' (además de 'pd').
- service-success: la entrega inmediata cubre 'pd' y 'vp'.
- PaymentMethodSelect: opción VP opcional (solo si el form pasa vpBalance);
  muestra coste en PV, insuficiencia y el saldo VP.
- SendGiftForm + página: pasan el saldo VP.
- i18n Pay: vp, vpCost, insufficientVp, balanceVp, errors.insufficientVp (es/en).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web-next/app/[locale]/send-gift/page.tsx

@@ -4,7 +4,7 @@ import { getTranslations, setRequestLocale } from 'next-intl/server'
 import { redirect, Link } from '@/i18n/navigation'
 import { getSession } from '@/lib/session'
 import { getGameCharacters } from '@/lib/characters'
-import { getDPointsBalance } from '@/lib/dpoints'
+import { getDPointsBalance, getVPointsBalance } from '@/lib/dpoints'
 import { getGiftCatalog } from '@/lib/gift'
 import { PageShell } from '@/components/PageShell'
 import { ServiceBox } from '@/components/ServiceBox'
@@ -27,10 +27,11 @@ export default async function SendGiftPage({ params }: { params: Promise<{ local
   if (!session.bnetId) redirect({ href: '/log-in', locale })
   if (!session.username) redirect({ href: '/select-account', locale })
 
-  const [chars, catalog, pdBalance] = await Promise.all([
+  const [chars, catalog, pdBalance, vpBalance] = await Promise.all([
     getGameCharacters(session.accountId!),
     getGiftCatalog(),
     getDPointsBalance(session.accountId!),
+    getVPointsBalance(session.accountId!),
   ])
   const currency = process.env.SUMUP_CURRENCY === 'EUR' ? '€' : process.env.SUMUP_CURRENCY || '€'
 
@@ -70,6 +71,7 @@ export default async function SendGiftPage({ params }: { params: Promise<{ local
           catalog={catalog}
           currency={currency}
           pdBalance={pdBalance}
+          vpBalance={vpBalance}
         />
       </ServiceBox>
     </PageShell>

web-next/app/[locale]/service-success/page.tsx

@@ -22,8 +22,8 @@ export default async function ServiceSuccessPage({
   let status: 'delivered' | 'already' | 'error' = 'error'
   let okName: string | null = null
   let service = urlService ?? null
-  if (provider === 'pd') {
-    // Pago con saldo PD: la entrega ya se ejecutó en el checkout; aquí solo se muestra.
+  if (provider === 'pd' || provider === 'vp') {
+    // Pago con saldo PD/PV: la entrega ya se ejecutó en el checkout; aquí solo se muestra.
     status = 'delivered'
     okName = name ?? null
   } else if (provider === 'sumup' && ref) {

web-next/app/api/gift/checkout/route.ts

@@ -4,7 +4,7 @@ import { getGameCharacters, getAccountIdByCharacterName } from '@/lib/characters
 import { checkSecurityToken } from '@/lib/security-token'
 import { createSumUpCheckout, sumupConfigured } from '@/lib/sumup'
 import { priceCart, isValidCharName, sendGiftByMail, type CartLine } from '@/lib/gift'
-import { payServiceWithDPoints } from '@/lib/pay-with-dpoints'
+import { payServiceWithDPoints, payServiceWithVPoints } from '@/lib/pay-with-dpoints'
 
 /**
  * Inicia el pago (SumUp) de un regalo. Condiciones:
@@ -62,16 +62,18 @@ export async function POST(request: Request) {
   const site = process.env.SITE_URL || ''
   const items = priced.lines.map((l) => ({ i: l.itemId, q: l.qty }))
 
-  // Pago con saldo PD: se descuenta el saldo y se envía el regalo al momento.
-  if (String(body.provider) === 'pd') {
-    const r = await payServiceWithDPoints(session.accountId, priced.total, () =>
-      sendGiftByMail(destination, source, items),
-    )
-    if (!r.success) return Response.json({ success: false, error: r.error, message: 'No se pudo completar el pago con PD.' })
+  // Pago con saldo PD o PV: se descuenta el saldo y se envía el regalo al momento.
+  // PV es más caro que PD (son puntos gratis por votar).
+  if (String(body.provider) === 'pd' || String(body.provider) === 'vp') {
+    const useVp = String(body.provider) === 'vp'
+    const r = useVp
+      ? await payServiceWithVPoints(session.accountId, priced.total, () => sendGiftByMail(destination, source, items))
+      : await payServiceWithDPoints(session.accountId, priced.total, () => sendGiftByMail(destination, source, items))
+    if (!r.success) return Response.json({ success: false, error: r.error, message: 'No se pudo completar el pago.' })
     const locale = String(body.locale) === 'en' ? 'en' : 'es'
     return Response.json({
       success: true,
-      url: `${site}/${locale}/service-success?service=send-gift&provider=pd&name=${encodeURIComponent(destination)}`,
+      url: `${site}/${locale}/service-success?service=send-gift&provider=${useVp ? 'vp' : 'pd'}&name=${encodeURIComponent(destination)}`,
     })
   }