feat: connect NWScript language server to Monaco via WebSocket

Add the forked nwscript-ee-language-server as a git submodule and wire
it up to the editor through a WebSocket-based LSP bridge:

- Backend: lsp.service.ts spawns the language server in --stdio mode
  and bridges JSON-RPC messages between WebSocket and stdin/stdout
- Backend: /ws/lsp upgrade handler in index.ts
- Frontend: LspClient class using vscode-ws-jsonrpc for JSON-RPC over
  WebSocket, with Monaco providers for completions, hover, and
  diagnostics
- Frontend: useLspClient/useLspDocument hooks integrated into
  MonacoEditor component

packages/frontend/package.json

@@ -15,7 +15,9 @@
     "monaco-editor": "^0.55.1",
     "react": "^19.0.0",
     "react-dom": "^19.0.0",
-    "react-router-dom": "^7.0.0"
+    "react-router-dom": "^7.0.0",
+    "vscode-languageserver-protocol": "^3.17.5",
+    "vscode-ws-jsonrpc": "^3.5.0"
   },
   "devDependencies": {
     "@types/react": "^19.0.0",