Implement DATEV export functionality in DataViewer and enhance TransactionsTable with selection features and improved row styling. Update environment variables and add devServer configuration in webpack for better development experience.

webpack.prod.config.js

@@ -72,6 +72,24 @@ module.exports = {
   resolve: {
     extensions: ['.js', '.jsx'],
   },
+  devServer: {
+    port: 5001,
+    host: '0.0.0.0',
+    allowedHosts: 'all',
+    historyApiFallback: true,
+    hot: false,
+    liveReload: false,
+    client: false,
+    static: {
+      directory: path.join(__dirname, 'client/public'),
+    },
+    proxy: {
+      '/api': {
+        target: 'http://localhost:5000',
+        changeOrigin: true,
+      },
+    },
+  },
   performance: {
     maxAssetSize: 512000,
     maxEntrypointSize: 512000,