fix: relancer les sources vides après purge

server/db.ts

@@ -1,4 +1,4 @@
-import { eq, and, desc, sql, inArray, getTableColumns } from "drizzle-orm";
+import { eq, and, desc, sql, inArray, getTableColumns, count } from "drizzle-orm";
 import { drizzle } from "drizzle-orm/mysql2";
 import { 
   InsertUser, 
@@ -231,6 +231,17 @@ export async function getSourceFileById(id: number): Promise<SourceFile | undefi
   return result[0];
 }
 
+/** Nombre de factures encore rattachées à une source PDF. */
+export async function countInvoicesBySourceFileId(sourceFileId: number): Promise<number> {
+  const db = await getDb();
+  if (!db) return 0;
+  const result = await db
+    .select({ value: count() })
+    .from(invoices)
+    .where(eq(invoices.sourceFileId, sourceFileId));
+  return Number(result[0]?.value ?? 0);
+}
+
 export async function updateSourceFile(id: number, data: Partial<SourceFile>) {
   const db = await getDb();
   if (!db) throw new Error("Database not available");