fix(biome): ignore Next.js auto-generated next-env.d.ts file

- Add **/next-env.d.ts to Biome ignore list
- Next.js generates this file with double quotes, conflicts with single quote config
- This is an auto-generated file that should not be manually formatted

Fixes format-check CI failures.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

packages/config/biome.json

@@ -15,7 +15,8 @@
       "**/coverage/**",
       "**/.turbo/**",
       "**/storybook-static/**",
-      "**/*.tsbuildinfo"
+      "**/*.tsbuildinfo",
+      "**/next-env.d.ts"
     ]
   },
   "formatter": {