feat: flag products whose last registered supplier differs from current view

Instead of unreliable preference=1, use artfou1.no_id DESC (most recently
added artfou1 entry) to identify the last supplier for each product.
Shows an amber warning icon in the Désignation column when the last
supplier ≠ current supplier view, with tooltip showing who to attribute
the sales to.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/types/grid.ts

@@ -33,6 +33,9 @@ export interface ProductRow {
     codein: string;
     codeFournisseur: string;
     nomFournisseur: string;
+    /** Dernier fournisseur enregistré pour cet article (artfou1.no_id DESC). Peut différer du fournisseur consulté. */
+    fournisseurPrincipalCode?: string;
+    fournisseurPrincipalNom?: string;
     libelle1: string;
     gtin: string;
     reference: string;