Issue #36 — Backend: Invoice Entity & Module Scaffold

[yusuftomilola]

Location: backend/src/invoices/

Description

ManageHub needs an Invoices module to maintain a permanent financial record for every successful payment on the platform. Each invoice is linked to a specific payment, booking, and member, and carries a human-readable invoice number that can be referenced in emails and PDF documents. This issue covers the foundational setup — the entity, enums, module, and bare service/controller stubs.

All monetary values must be stored in kobo as integers alongside a derived Naira value for convenience in display and PDF generation. The synchronize: true flag handles schema changes automatically.

Acceptance Criteria

• An Invoice entity is created at backend/src/invoices/entities/invoice.entity.ts with the following fields:
  • id — UUID, primary key, auto-generated
  • invoiceNumber — string, unique — human-readable identifier (e.g. MH-INV-20260318-0001)
  • amountKobo — integer, required
  • amountNaira — decimal/float, required (derived from amountKobo / 100)
  • status — enum: PAID, PENDING — default PENDING
  • paidAt — timestamp, nullable
  • userId — UUID, foreign key referencing users
  • bookingId — UUID, foreign key referencing bookings
  • paymentId — UUID, foreign key referencing payments, nullable
  • user — @ManyToOne relation to User entity
  • booking — @ManyToOne relation to Booking entity
  • payment — @ManyToOne relation to Payment entity, nullable
  • createdAt / updatedAt — auto timestamps
• An InvoiceStatus enum is created at backend/src/invoices/enums/invoice-status.enum.ts
• An InvoicesModule is created at backend/src/invoices/invoices.module.ts with TypeOrmModule.forFeature([Invoice]) registered
• An InvoicesService stub is created at backend/src/invoices/providers/invoices.service.ts
• An InvoicesController stub is created at backend/src/invoices/invoices.controller.ts with the @Controller('invoices') decorator
• InvoicesModule is imported into backend/src/app.module.ts
• npx tsc --noEmit passes with no errors