feat: replace Iyzico with Stripe + single-page subscription stepper

Subscription/checkout flow rewritten end-to-end. The plan-card "Devam Et"
button silently wiped brand selection on re-click and the actual proceed
button lived offscreen — fixed by collapsing plan/brands/payment/confirm
into a single vertical stepper with one sticky CTA.

Backend
- Stripe Hosted Checkout (`/payments/stripe/checkout`) + webhook
  (`/payments/stripe/webhook`, raw body) replacing the stubbed Iyzico
  module. Webhook activates subscription on `checkout.session.completed`,
  expires the pending subscription on cancel/expire so users can retry.
- New `bank_accounts` table — multiple rows, single `is_active` enforced
  by a partial unique index. Admin CRUD under `/admin/bank-accounts`
  with multipart QR upload to MinIO; atomic `/activate` swap in a
  transaction; `GET /payments/bank-info` returns the active row.
- `payments` gains `stripe_session_id`, `stripe_payment_intent_id`,
  `bank_account_id`. EFT flow now reads the active bank account at
  payment time and stores the FK for reconciliation.
- Env: `IYZICO_*` removed, `STRIPE_*` added (validated by zod schema).
- `main.ts` `rawBody: true` for Stripe signature verification.
- Drizzle 0003 snapshot id collision fixed (VIEW-only migration shared
  prevId with 0002, blocking new generates).

Frontend
- `/dashboard/subscription` rewritten as a 4-step vertical stepper with
  step-aware sticky bottom CTA; plan re-selection is idempotent and
  preserves brand state. `/dashboard/subscription/pay` deleted; Stripe
  returns to the same page via `?stripe=success|cancelled` and the UI
  polls `/subscriptions/me` until the webhook activates the row.
- New components: `bank-transfer-card.tsx` (DB-driven IBAN + Kolay Adres
  + uploaded QR image + receipt upload) and `stripe-checkout-button.tsx`.
- Active subscription view, trial onboarding/urgency banner, downgrade
  and cancel dialogs preserved.
- TR/EN i18n: new `subscription.steps.*`, `subscription.stickyCta.*`,
  `payment.stripe.*`, `payment.bank.*`; provider label updated.

PostHog: `method: "iyzico"` → `"stripe"`; new events `iban_copied`,
`kolay_adres_copied`, `qr_viewed`, `eft_initiated`,
`stripe_redirect_returned`.

Deploy runs `db:migrate` which applies 0004_hot_quicksilver
(additive: new table + nullable columns; safe to apply on prod).
Operator must add `STRIPE_SECRET_KEY`, `STRIPE_PUBLISHABLE_KEY`,
`STRIPE_WEBHOOK_SECRET` to env and create the first
`bank_accounts` row via the admin endpoint before the bank tab works.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/api/src/database/schema/core.ts

@@ -162,6 +162,28 @@ export const userBrands = pgTable(
   ],
 );
 
+// ─── Bank Accounts (EFT/Havale destination accounts, one active at a time) ────
+export const bankAccounts = pgTable(
+  "bank_accounts",
+  {
+    id: uuid("id").primaryKey().defaultRandom(),
+    bankName: varchar("bank_name", { length: 100 }).notNull(),
+    accountHolder: varchar("account_holder", { length: 200 }).notNull(),
+    iban: varchar("iban", { length: 34 }).notNull(),
+    kolayAdres: varchar("kolay_adres", { length: 100 }),
+    kolayAdresType: varchar("kolay_adres_type", { length: 20 }),
+    qrImageUrl: text("qr_image_url"),
+    descriptionTemplate: varchar("description_template", { length: 200 })
+      .notNull()
+      .default("SASE-{{paymentId}}"),
+    isActive: boolean("is_active").default(false).notNull(),
+    displayOrder: integer("display_order").default(0).notNull(),
+    createdAt: timestamp("created_at", { withTimezone: true }).defaultNow().notNull(),
+    updatedAt: timestamp("updated_at", { withTimezone: true }).defaultNow().notNull(),
+  },
+  (table) => [index("bank_accounts_active_idx").on(table.isActive)],
+);
+
 // ─── Payments ───────────────────────────────────────
 export const payments = pgTable(
   "payments",
@@ -178,6 +200,9 @@ export const payments = pgTable(
     method: varchar("method", { length: 20 }).notNull(),
     status: varchar("status", { length: 20 }).default("pending").notNull(),
     iyzicoPaymentId: text("iyzico_payment_id"),
+    stripeSessionId: text("stripe_session_id"),
+    stripePaymentIntentId: text("stripe_payment_intent_id"),
+    bankAccountId: uuid("bank_account_id").references(() => bankAccounts.id),
     eftReceiptUrl: text("eft_receipt_url"),
     adminNote: text("admin_note"),
     createdAt: timestamp("created_at", { withTimezone: true }).defaultNow().notNull(),
@@ -186,6 +211,7 @@ export const payments = pgTable(
   (table) => [
     index("payments_user_id_idx").on(table.userId),
     index("payments_status_idx").on(table.status),
+    index("payments_stripe_session_id_idx").on(table.stripeSessionId),
   ],
 );
 

apps/api/src/database/schema/relations.ts

@@ -1,6 +1,7 @@
 import { relations } from "drizzle-orm";
 import {
   accounts,
+  bankAccounts,
   brands,
   catalogVehicles,
   categories,
@@ -75,6 +76,14 @@ export const paymentsRelations = relations(payments, ({ one }) => ({
     fields: [payments.subscriptionId],
     references: [userSubscriptions.id],
   }),
+  bankAccount: one(bankAccounts, {
+    fields: [payments.bankAccountId],
+    references: [bankAccounts.id],
+  }),
+}));
+
+export const bankAccountsRelations = relations(bankAccounts, ({ many }) => ({
+  payments: many(payments),
 }));
 
 export const queryLogsRelations = relations(queryLogs, ({ one }) => ({