Improve invoice verification caching with conflict resolution and error handling

Implement unique constraint on invoice verification cache key and handle duplicate entries gracefully in the backend.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: d43bd811-9372-45a7-8ac9-4a954c0538e1
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shared/schema.ts

@@ -160,7 +160,7 @@ export const nocodbConfig = pgTable("nocodb_config", {
 // Cache de vérification des factures
 export const invoiceVerificationCache = pgTable("invoice_verification_cache", {
   id: serial("id").primaryKey(),
-  cacheKey: varchar("cache_key", { length: 255 }).notNull(),
+  cacheKey: varchar("cache_key", { length: 255 }).notNull().unique(),
   groupId: integer("group_id").notNull(),
   invoiceReference: varchar("invoice_reference", { length: 255 }).notNull(),
   supplierName: varchar("supplier_name", { length: 255 }),