feat(release): implement semantic versioning automation with conventional commits

- Add semantic-release for automated npm publishing
- Add commitlint + husky for commit message enforcement
- Add professional branching strategy (beta → main workflow)
- Create .releaserc.json with multi-branch config
- Create sync-version-plugin.cjs for VERSION file sync
- Update release.yml workflow (Node.js 22 required)
- Update CLAUDE.md and CONTRIBUTING.md with new workflow
- Deprecate manual bump-version.sh script

.github/workflows/release.yml

@@ -0,0 +1,51 @@
+name: Release
+
+on:
+  push:
+    branches:
+      - main
+      - beta
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: write
+      issues: write
+      pull-requests: write
+      id-token: write
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          persist-credentials: false
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+          registry-url: 'https://registry.npmjs.org'
+
+      - name: Setup Bun
+        uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: latest
+
+      - name: Install dependencies
+        run: bun install --frozen-lockfile
+
+      - name: Build package
+        run: bun run build
+
+      - name: Validate (typecheck + lint + tests)
+        run: bun run validate
+
+      - name: Release
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
+          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
+        run: bunx semantic-release