fix: Correct attribute name in betting outcomes API

- Fixed 'MatchOutcomeModel' object has no attribute 'column_value' error
- Changed outcome.column_value to outcome.float_value to match database model
- API endpoint /api/cashier/available-matches now works correctly

mbetterclient/web_dashboard/routes.py

@@ -2769,7 +2769,7 @@ def get_available_matches_for_betting():
                     betting_outcomes.append({
                         'outcome_id': outcome.id,
                         'outcome_name': outcome.column_name,
-                        'outcome_value': outcome.column_value,
+                        'outcome_value': outcome.float_value,
                         'display_name': outcome.column_name  # Use actual outcome name from database
                     })