Repair Service Sale Order Sync

OCA repair_service pushes service (labor) lines to the sale order only at "Create Quotation" time — services added, changed, or removed on the repair order afterwards never reach the customer-facing quotation.

This module keeps them in sync, mirroring the behavior core Odoo implements for spare parts (stock.move ↔ sale.order.line):

• each repair.service remembers its generated sale_line_id;

• services created while a sale order exists immediately add a line;

• quantity / product / unit / description changes update the linked line;

• deleting a service zeroes the linked line's quantity (not deleted, so confirmed orders keep their audit trail).

Auto-installs with repair_service.