Add a Language Server Protocol (LSP) server to enable IDE integration.
The server provides:
- Real-time diagnostics (parse errors and type errors)
- Basic hover information
- Keyword completions (fn, let, if, match, type, effect, etc.)
- Go-to-definition stub (ready for implementation)
Usage: lux --lsp
The LSP server can be integrated with any editor that supports LSP,
including VS Code, Neovim, Emacs, and others.
Dependencies added:
- lsp-server 0.7
- lsp-types 0.94
- serde with derive feature
- serde_json
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
