fix: Rename chat.css to style.css in chat package build (#16622) (no-changelog)

Co-authored-by: cubic-dev-ai[bot] <191113872+cubic-dev-ai[bot]@users.noreply.github.com>

packages/frontend/@n8n/chat/vite.config.mts

@@ -1,5 +1,6 @@
 import { defineConfig, mergeConfig } from 'vite';
 import { resolve } from 'path';
+import { renameSync } from 'fs';
 import vue from '@vitejs/plugin-vue';
 import icons from 'unplugin-icons/vite';
 import dts from 'vite-plugin-dts';
@@ -18,6 +19,21 @@ export default mergeConfig(
 				autoInstall: true,
 			}),
 			dts(),
+			{
+				name: 'rename-css-file',
+				closeBundle() {
+					// The chat.css is automatically named based on vite.config.ts library name.
+					// ChatTrigger Node requires https://cdn.jsdelivr.net/npm/@n8n/chat/dist/style.css
+					// As such for backwards compatibility, we need to maintain the same name file
+					const cssPath = resolve(__dirname, 'dist', 'chat.css');
+					const newCssPath = resolve(__dirname, 'dist', 'style.css');
+					try {
+						renameSync(cssPath, newCssPath);
+					} catch (error) {
+						console.error('Failed to rename chat.css file:', error);
+					}
+				},
+			},
 		],
 		resolve: {
 			alias: {