feat(billing): integrate Stripe for subscription management and billing access

- Added billing-related fields to the User model in the database.
- Implemented functions for managing billing access, including trial periods and subscription statuses.
- Created new billing utility functions for Stripe integration.
- Updated onboarding page to include billing overview and workspace creation eligibility.
- Enhanced route access checks to require billing access for certain actions.
- Implemented cleanup scripts for expired billing workspaces and associated media.
- Updated header component to conditionally show app navigation based on billing access.
- Added new migrations for billing-related database changes.

prisma/schema.prisma

@@ -22,6 +22,16 @@ model User {
   createdAt     DateTime  @default(now())
   updatedAt     DateTime  @updatedAt
   onboardingCompletedAt DateTime?
+  trialEndsAt DateTime?
+  billingTrialConsumedAt DateTime?
+  stripeCustomerId String? @unique
+  stripeSubscriptionId String? @unique
+  stripePriceId String?
+  stripeCurrentPeriodEnd DateTime?
+  stripeCancelAtPeriodEnd Boolean @default(false)
+  stripeCancelAt DateTime?
+  billingAccessEndedAt DateTime?
+  subscriptionStatus BillingSubscriptionStatus @default(FREE)
 
   // Relations
   accounts           Account[]
@@ -44,6 +54,17 @@ model User {
   @@map("users")
 }
 
+enum BillingSubscriptionStatus {
+  FREE
+  TRIALING
+  ACTIVE
+  PAST_DUE
+  CANCELED
+  UNPAID
+  INCOMPLETE
+  INCOMPLETE_EXPIRED
+}
+
 enum FeedbackEntryType {
   FEEDBACK
   REVIEW