react-ace v14 is CommonJS-only with no ESM entry point, making it
fundamentally incompatible with Vite's ESM-first dev server. Every
CJS interop workaround failed. Switched to @uiw/react-codemirror v4.25
which ships proper dual ESM+CJS and works with Vite out of the box.
Changes:
- Remove ace-builds and react-ace dependencies
- Add @uiw/react-codemirror + 16 @codemirror/lang-* packages
- Add @uiw/codemirror-theme-tomorrow-night-blue (closest to ACE's 'tomorrow')
- Add @replit/codemirror-lang-csharp for C# support
- Rewrite EditorPanel.tsx: delete 108 lines of ACE boilerplate
(?url imports, setModuleUrl, CJS interop hack), replace with
~30 lines of clean CodeMirror language extension setup
- Delete vite.d.ts (only needed for ACE ?url import types)
- Remove optimizeDeps.include from vite.config.ts (not needed for CM)
- Add CodeMirror flex layout CSS to index.css
Supported languages: JavaScript/JSX, TypeScript/TSX, Python, JSON,
HTML, CSS, Less, YAML, Markdown, SQL, Java, Go, Rust, C/C++, C#,
PHP, XML. Unsupported types fall back to plain text.
Verified: tsc clean, vite build passes, heartbeat worker intact.
