Release 0.3.1: Electron desktop app launchable

- yarn start:electron works (native rebuild + bundle verified)
- Pinned electron devDependency, tracked packaging scripts

package.json

@@ -1,7 +1,7 @@
 {
   "private": true,
   "name": "modula2-ide",
-  "version": "0.3.0",
+  "version": "0.3.1",
   "description": "GNU Modula-2 IDE built on Eclipse Theia",
   "engines": {
     "node": ">=24",