feat: improve semantic-release automation and disable manual version bumping

- Add custom semantic-release plugin to sync installer package.json
- Update semantic-release config to include installer package.json in releases
- Disable manual version bump script in favor of conventional commits
- Add helper script for version synchronization
- This ensures semantic-release fully manages both package.json files

BREAKING CHANGE: Manual version bumping via npm scripts is now disabled. Use conventional commits for automated releases.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

.releaserc.json

@@ -5,10 +5,11 @@
     "@semantic-release/release-notes-generator",
     "@semantic-release/changelog",
     "@semantic-release/npm",
+    "./tools/semantic-release-sync-installer.js",
     [
       "@semantic-release/git",
       {
-        "assets": ["package.json", "package-lock.json", "CHANGELOG.md"],
+        "assets": ["package.json", "package-lock.json", "tools/installer/package.json", "CHANGELOG.md"],
         "message": "chore(release): ${nextRelease.version} [skip ci]\n\n${nextRelease.notes}"
       }
     ],