fix(subscription): recover stepper when a pending checkout is abandoned

A user who picked a plan + brands, clicked the checkout button to
create the pending subscription, then closed the tab without paying
came back to a frozen "Mevcut Plan · Bekliyor" card with no payment
button and no way to edit. Status was "pending", which my conditional
treated as an active subscription and routed away from the stepper.

Frontend
- hasActiveSub narrowed to active|cancelled only. Pending users now
  see the stepper again.
- New effect pre-fills selectedPlanKey, selectedBrandIds,
  billingPeriod from the pending row on first render and jumps
  straight to the payment step.
- New PendingPaymentBanner at the top of the stepper with
  "Odemeye devam et" (scrolls + sets step=payment) and "Vazgec"
  (calls cancel-pending then resets selection).

Backend
- subscriptions.service.create() auto-expires existing pending
  rows for the user before inserting a new one — abandoned checkouts
  no longer accumulate and a fresh attempt with a different plan
  doesn't 409.
- New PATCH /subscriptions/cancel-pending + service method for
  the banner's explicit cancel action.

i18n: subscription.pendingBanner.* (tr/en).

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

apps/api/src/subscriptions/subscriptions.controller.ts

@@ -39,6 +39,11 @@ export class SubscriptionsController {
     return this.subscriptionsService.startFullTrial(userId);
   }
 
+  @Patch("cancel-pending")
+  async cancelPending(@CurrentUser("id") userId: string) {
+    return this.subscriptionsService.cancelPending(userId);
+  }
+
   @Patch("cancel")
   async cancel(@CurrentUser("id") userId: string) {
     return this.subscriptionsService.cancel(userId);

apps/api/src/subscriptions/subscriptions.service.ts

@@ -34,6 +34,13 @@ export class SubscriptionsService {
       .set({ status: "expired", updatedAt: new Date() })
       .where(and(eq(userSubscriptions.userId, userId), eq(userSubscriptions.status, "trial")));
 
+    // Expire any existing pending subscription so an abandoned checkout
+    // doesn't block the user from starting a new one with different choices.
+    await this.db
+      .update(userSubscriptions)
+      .set({ status: "expired", updatedAt: new Date() })
+      .where(and(eq(userSubscriptions.userId, userId), eq(userSubscriptions.status, "pending")));
+
     // Validate plan
     const plan = await this.db.select().from(plans).where(eq(plans.id, data.planId)).limit(1);
     if (plan.length === 0) throw new NotFoundException("Plan bulunamadı");
@@ -157,6 +164,15 @@ export class SubscriptionsService {
     return { ...sub, plan: plan[0], brands: subBrands };
   }
 
+  async cancelPending(userId: string) {
+    const result = await this.db
+      .update(userSubscriptions)
+      .set({ status: "expired", updatedAt: new Date() })
+      .where(and(eq(userSubscriptions.userId, userId), eq(userSubscriptions.status, "pending")))
+      .returning({ id: userSubscriptions.id });
+    return { cancelled: result.length };
+  }
+
   async cancel(userId: string) {
     const [sub] = await this.db
       .select()