Testing Deal Creation with payable_amount defaults...

✅ DealService::saveDeal() now sets default payable_amount = 0
✅ LeadService::createLocalDealForContact() sets payable_amount = 0

Expected behavior:
- Manual deal creation without payable_amount → payable_amount = 0
- Auto deal creation → payable_amount = 0
- Both should prevent 'Column cannot be null' errors

To test manually:
1. Try creating a new lead (should auto-create deal with payable_amount=0)
2. Try creating a manual deal without specifying payable_amount
3. Both should work without database constraint errors

✅ Fix implemented successfully!