Customer: consolidate GetCustomerCompanyId onto auth helper

[CryptoJones]

Summary

GetCustomerCompanyId in customercontroller.js uses raw sequelize.query, while auth.js uses Sequelize models + defaultScope. Behavior should match, but the split increases maintenance cost.

Proposed fix

Replace raw SQL with auth.getCompanyIdByCustomerId() (or shared helper).

Acceptance criteria

• No raw SQL for customer company lookup in customer controller
• Existing customer auth tests pass

Source

Code review backlog (2026-06-23)