Prevent csv export injections (#14347)

**Small Security Issue:** CSV exports were vulnerable to formula
injection attacks when users entered values starting with =, +, -, or @.
(only happens if a logged-in user injects corrupted data)

Solution:
- Added ZWJ (Zero-Width Joiner) protection that prefixes dangerous
values with invisible Unicode character
- This is the best way to preserve original data while preventing Excel
from executing formulas
- Added import cleanup to restore original values when re-importing
 
Changes:
- New sanitizeValueForCSVExport() function for security
- Updated all CSV export paths to use both security + formatting
functions
- Added comprehensive tests covering attack vectors and international
characters
- Also added cursor rules for better code consistency

---------

Co-authored-by: Charles Bochet <charlesBochet@users.noreply.github.com>

packages/twenty-front/src/modules/spreadsheet-import/steps/components/UploadStep/hooks/useDownloadFakeRecords.ts

@@ -3,7 +3,8 @@ import { spreadsheetImportFilterAvailableFieldMetadataItems } from '@/object-rec
 import { getCompositeSubFieldLabelWithFieldLabel } from '@/object-record/spreadsheet-import/utils/spreadsheetImportGetCompositeSubFieldLabelWithFieldLabel';
 import { SETTINGS_COMPOSITE_FIELD_TYPE_CONFIGS } from '@/settings/data-model/constants/SettingsCompositeFieldTypeConfigs';
 import { SETTINGS_NON_COMPOSITE_FIELD_TYPE_CONFIGS } from '@/settings/data-model/constants/SettingsNonCompositeFieldTypeConfigs';
-import { escapeCSVValue } from '@/spreadsheet-import/utils/escapeCSVValue';
+import { formatValueForCSV } from '@/spreadsheet-import/utils/formatValueForCSV';
+import { sanitizeValueForCSVExport } from '@/spreadsheet-import/utils/sanitizeValueForCSVExport';
 import { saveAs } from 'file-saver';
 import { FieldMetadataType } from 'twenty-shared/types';
 
@@ -122,7 +123,9 @@ export const useDownloadFakeRecords = () => {
 
   const formatToCsvContent = (rows: string[][]) => {
     const escapedRows = rows.map((row) => {
-      return row.map((value) => escapeCSVValue(value));
+      return row.map((value) =>
+        formatValueForCSV(sanitizeValueForCSVExport(value)),
+      );
     });
 
     const csvContent = [...escapedRows.map((row) => row.join(','))].join('\n');