fix: use json-2-csv built-in excelBOM option for UTF-8 BOM support

Instead of manually prepending \uFEFF to the Blob, use the library's
built-in excelBOM option which handles BOM prepending at the CSV
generation level. This is cleaner and ensures BOM is included regardless
of how the CSV string is consumed downstream.

Fixes #19230

https://claude.ai/code/session_01DXL7ohePLgJoWVSBWU5Cgm

packages/twenty-front/src/modules/object-record/record-index/export/hooks/__tests__/useRecordIndexExportRecords.test.ts

@@ -63,7 +63,7 @@ describe('generateCsv', () => {
     ];
     const csv = generateCsv({ columns, rows });
     expect(csv)
-      .toEqual(`Id,Foo,Empty,Nested link field / Link URL,Nested link field / Secondary Links,Relation
+      .toEqual(`\uFEFFId,Foo,Empty,Nested link field / Link URL,Nested link field / Secondary Links,Relation
 1,some field,,https://www.test.com,"[{""label"":""secondary link 1"",""url"":""https://www.test.com""},{""label"":""secondary link 2"",""url"":""https://www.test.com""}]",a relation`);
   });
 
@@ -166,6 +166,47 @@ describe('generateCsv', () => {
     expect(csv).toContain('1,John Doe,[],[]');
   });
 
+  it('prepends UTF-8 BOM for Excel compatibility', () => {
+    const columns: Pick<
+      ColumnDefinition<FieldMetadata>,
+      'size' | 'label' | 'type' | 'metadata'
+    >[] = [
+      {
+        label: 'Name',
+        size: 100,
+        type: FieldMetadataType.TEXT,
+        metadata: { fieldName: 'name' },
+      },
+    ];
+
+    const csv = generateCsv({ columns, rows: [{ id: '1', name: 'test' }] });
+
+    expect(csv.charCodeAt(0)).toBe(0xfeff);
+  });
+
+  it.each([
+    ['Arabic', 'مرحبا'],
+    ['Chinese', '你好'],
+    ['Japanese', 'こんにちは'],
+    ['Korean', '안녕하세요'],
+  ])('preserves %s characters in generated CSV', (_, name) => {
+    const columns: Pick<
+      ColumnDefinition<FieldMetadata>,
+      'size' | 'label' | 'type' | 'metadata'
+    >[] = [
+      {
+        label: 'Name',
+        size: 100,
+        type: FieldMetadataType.TEXT,
+        metadata: { fieldName: 'name' },
+      },
+    ];
+
+    const csv = generateCsv({ columns, rows: [{ id: '1', name }] });
+
+    expect(csv).toContain(name);
+  });
+
   describe('CSV Injection Prevention with ZWJ', () => {
     it('prevents formula injection with equals sign using ZWJ prefix', () => {
       const columns: Pick<

packages/twenty-front/src/modules/object-record/record-index/export/hooks/useRecordIndexExportRecords.ts

@@ -114,6 +114,7 @@ export const generateCsv: GenerateExport = ({
   return json2csv(sanitizedRows, {
     keys,
     emptyFieldValue: '',
+    excelBOM: true,
     // Note: We handle CSV injection prevention manually with ZWJ approach above
     // This preserves original which the csvSecurity option does not do
   });