Add unit tests for TransactionsController

[MissBlue00]

Task

Add unit test coverage for the TransactionsController endpoints.

Details

• Create apps/api/src/transactions/transactions.controller.spec.ts
• Test GET /transactions returns paginated list
• Test GET /transactions/:id returns single transaction
• Test filtering by type, status, and date range
• Test 404 when transaction not found
• Mock TransactionsService responses

Path

• apps/api/src/transactions/transactions.controller.spec.ts

Test

Run pnpm --filter api test to verify.