Add Factory Droid to README, bump to 0.4.0, add npm publish workflow

- Document Droid as third converter target alongside OpenCode and Codex
- Bump package version 0.3.0 → 0.4.0 for new target feature
- Add CHANGELOG entry for 2.32.0 with Droid details
- Add GitHub Actions workflow to publish to npm on release

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@every-env/compound-plugin",
-  "version": "0.3.0",
+  "version": "0.4.0",
   "type": "module",
   "private": false,
   "bin": {