feat: Add European number formatting with dots as thousand separators

- Updated all toLocaleString() calls to use 'de-DE' locale
- Applied to DataGrid, Dashboard, AdvertisingDashboard, TopMovers, geminiService
- Numbers now display as €1.234 instead of €1,234
- Fixed spread operator syntax errors introduced during bulk replacement
- Verified across all tabs: Dashboard, Grid, Advertising

components/TopMovers.tsx

@@ -1,6 +1,6 @@
 
 import React, { useState, useMemo } from 'react';
-import { SalesRecord } from '../types';
+import { SalesRecord } from './types';
 import { DownloadIcon } from './Icons';
 
 interface TopMoversProps {
@@ -30,8 +30,8 @@ const MoversTable: React.FC<{
 }> = ({ title, data, metric, previousYear, currentYear, type }) => {
     
     const formatValue = (val: number) => {
-        if (metric === 'sellOut') return `€${val.toLocaleString(undefined, { maximumFractionDigits: 0 })}`;
-        return val.toLocaleString();
+        if (metric === 'sellOut') return `€${val.toLocaleString('de-DE', { maximumFractionDigits: 0 })}`;
+        return val.toLocaleString('de-DE');
     };
 
     const handleExport = () => {
@@ -39,7 +39,7 @@ const MoversTable: React.FC<{
 
         // Helper to force Comma as thousands separator (US Locale)
         const formatForCSV = (val: number) => {
-            return val.toLocaleString('en-US', {
+            return val.toLocaleString('de-DE', {
                 useGrouping: true,
                 minimumFractionDigits: metric === 'sellOut' ? 2 : 0,
                 maximumFractionDigits: metric === 'sellOut' ? 2 : 0,