Release 0.5.0: Phase 3 complete (preferences + tasks)

- Modula-2 preference section: compiler path/options, dialect
- Task provider: Build/Clean/Rebuild/Run from modula2.json
- Verified end-to-end: prefs render, tasks list and execute gm2

package.json

@@ -1,7 +1,7 @@
 {
   "private": true,
   "name": "modula2-ide",
-  "version": "0.4.0",
+  "version": "0.5.0",
   "description": "GNU Modula-2 IDE built on Eclipse Theia",
   "engines": {
     "node": ">=24",