Storefront modal + email templating: theme extension, redesign, editable receipt

Storefront (theme app extension recesso-storefront):
- App block + app embed che linkano a /apps/recesso; modal via iframe con
  fallback progressive-enhancement; apertura immediata, dimensione fissa
- Redesign form: pattern modal moderno (header/footer fissi, corpo scorrevole),
  modalita' embed, popover info "i", testo ridotto, de-AI, trattini al posto degli em-dash

Ricevuta email:
- Dati per-shop dinamici da Shopify (nome, url, link stato ordine) via getShopInfo + statusPageUrl
- Template editabili VINCOLATI (oggetto/introduzione/nota) con segnaposto; layout
  fisso e conforme (dichiarazione, timestamp, avviso art. 54-bis)
- Pagina admin (Polaris) con anteprima live + ripristina default
- Campi email in Settings (Prisma) + migrazioni

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Mv83a29B4eFv5ixoj6PoE1

app/prisma/migrations/20260707092205_email_settings/migration.sql

@@ -0,0 +1,3 @@
+-- AlterTable
+ALTER TABLE "Settings" ADD COLUMN     "emailCustomMessage" TEXT,
+ADD COLUMN     "emailSenderName" TEXT;

app/prisma/migrations/20260707093246_email_logo/migration.sql

@@ -0,0 +1,2 @@
+-- AlterTable
+ALTER TABLE "Settings" ADD COLUMN     "emailLogoUrl" TEXT;

app/prisma/migrations/20260707094749_remove_email_logo/migration.sql

@@ -0,0 +1,8 @@
+/*
+  Warnings:
+
+  - You are about to drop the column `emailLogoUrl` on the `Settings` table. All the data in the column will be lost.
+
+*/
+-- AlterTable
+ALTER TABLE "Settings" DROP COLUMN "emailLogoUrl";

app/prisma/migrations/20260707095341_email_templates/migration.sql

@@ -0,0 +1,12 @@
+/*
+  Warnings:
+
+  - You are about to drop the column `emailCustomMessage` on the `Settings` table. All the data in the column will be lost.
+  - You are about to drop the column `emailSenderName` on the `Settings` table. All the data in the column will be lost.
+
+*/
+-- AlterTable
+ALTER TABLE "Settings" DROP COLUMN "emailCustomMessage",
+DROP COLUMN "emailSenderName",
+ADD COLUMN     "emailBodyTemplate" TEXT,
+ADD COLUMN     "emailSubjectTemplate" TEXT;

app/prisma/migrations/20260707100338_email_text_fields/migration.sql

@@ -0,0 +1,13 @@
+/*
+  Warnings:
+
+  - You are about to drop the column `emailBodyTemplate` on the `Settings` table. All the data in the column will be lost.
+  - You are about to drop the column `emailSubjectTemplate` on the `Settings` table. All the data in the column will be lost.
+
+*/
+-- AlterTable
+ALTER TABLE "Settings" DROP COLUMN "emailBodyTemplate",
+DROP COLUMN "emailSubjectTemplate",
+ADD COLUMN     "emailIntro" TEXT,
+ADD COLUMN     "emailNote" TEXT,
+ADD COLUMN     "emailSubject" TEXT;

app/prisma/schema.prisma

@@ -49,6 +49,9 @@ model Settings {
   returnAddress      String?
   defaultWindowDays  Int      @default(14)
   withdrawalInfoText String?
+  emailSubject       String?
+  emailIntro         String?
+  emailNote          String?
   createdAt          DateTime @default(now())
   updatedAt          DateTime @updatedAt