[kvlonge]

Why

The README example test used @mock_orders(), a macro the README never explains, and its payments mock did not match the real source columns.

Changes

• The example model uses the real cents_to_dollars macro, and the README shows its Python file from the waffle-shop example.
• The test uses inline mock rows matching the real raw__orders and raw__payments columns, and expects the macro result.

Verification

• The exact README model and test compile and pass with sqb 0.134.6 on a copy of the waffle-shop example; changing the expected dollars makes the test fail.