test: reproduce dropped customer-supplied intent

[ShiboSoftwareDev]

Summary

• add the smallest schema-level reproduction for a non-catalog assembly component
• use the Kontron OSM-S-AM62L module as the concrete manufacturer-part-number example
• record the intended customer_supplied flag without changing the schema

Current behavior

Zod accepts the source component object but silently strips customer_supplied. Downstream BOM and assembly exporters therefore cannot distinguish a customer-supplied module from a part expected to exist in the assembly supplier's catalog.

The test.failing assertion makes that data loss explicit. This is separate from do_not_place: a customer-supplied component may still need placement and must remain in the engineering BOM.

Validation

• bun test ./tests/source_component_customer_supplied.test.ts
• current schema reproduces the expected failure and Bun reports the test.failing case as passing