chore: bump crate and extension versions to 0.5.0

Catches the workspace and the extension manifests up to the v0.5.x
release line (was still showing 0.2.0).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

extension/package.json

@@ -1,6 +1,6 @@
 {
   "name": "relicario-extension",
-  "version": "0.2.0",
+  "version": "0.5.0",
   "private": true,
   "scripts": {
     "build": "webpack --mode production",