Fix inverted transaction status logic

[kevintang513]

Summary

• Fixed critical bug where payment and request transaction logic was inverted in createTransaction()
• Payments now correctly complete immediately, requests stay pending as expected
• All unit tests passing (previously 2 failures)

Changes

File: backend/database.ts

• Line 549: Changed condition from isRequestTransaction(transaction) to isPayment(transaction)

Root Cause:
The transaction creation logic was checking for request transactions when it should have been checking for payment transactions. This caused:

• Payments to incorrectly remain in pending status (should be complete)
• Requests to incorrectly be marked complete immediately (should be pending until accepted)

Solution:
Use isPayment(transaction) instead of isRequestTransaction(transaction) to properly identify when to:

1. Debit sender's balance
2. Credit receiver's balance
3. Mark transaction status as complete
4. Send "received" notification

Request transactions correctly skip this logic and remain pending until explicitly accepted via updateTransactionById().

Test Plan

1. Run unit tests to verify fix:

   npm run test:unit:ci

   • ✅ should create a payment - expects status "complete"
   • ✅ should create a request - expects status "pending"
   • ✅ All 44 tests passing

2. Manual testing:

   npm run dev

   • Create a payment transaction → should complete immediately with balance changes
   • Create a request transaction → should stay pending, no balance change until accepted

3. Integration tests should continue to pass:

   npm run test:api

🤖 Generated with Claude Code

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❌ kevintang513
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