Release 0.9.0: server-side semantic diagnostics

- duplicate-declaration and unknown-identifier errors live in the editor
- enum literals resolve, complete and appear in the outline

package.json

@@ -1,7 +1,7 @@
 {
   "private": true,
   "name": "modula2-ide",
-  "version": "0.8.0",
+  "version": "0.9.0",
   "description": "GNU Modula-2 IDE built on Eclipse Theia",
   "engines": {
     "node": ">=24",