Signup route

[nanaabdul1172]

closes #713

Current State ✅
Imports are present - The signup route file already has all the required imports on lines 13-16:

import {
validateReferralCode,
referralCodeExists,
getReferralCodeOwner,
generateReferralCode,
} from '@/lib/referral';
Functions exist and are exported - All three functions (validateReferralCode, referralCodeExists, getReferralCodeOwner) are properly exported from
referral.ts

TypeScript compilation succeeds - No diagnostics or errors were found in either file

Tests already exist - Comprehensive tests in
signup.test.ts
cover:

✅ Successful signup with valid referral code
✅ Invalid referral code format rejection
✅ Non-existent referral code rejection
✅ Self-referral prevention
✅ Signup without referral code
Acceptance Criteria Met ✅
✅ All three referral helpers are imported and resolve correctly
✅ TypeScript compilation succeeds with no missing-module errors
✅ Test covering the full signup path with a valid referral code exists

[RUKAYAT-CODER]

Great job so far!
Kindly fix the workflow to pass