517e452c64
Introduce a shared InventoryDuplicateMatcher (SKU, manufacturer part number, manufacturer color) used by both manual inventory creation and powder-label scanning, so the two paths flag duplicates consistently. Surfaces a duplicate warning in the Create/Edit forms via inventory-duplicate-check.js and the catalog-lookup / label-scan flows. Callers pass tenant-restricted inventory; the matcher re-checks CompanyId as defense in depth. Adds InventoryDuplicateMatcherTests covering the match precedence. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>