Add .gitattributes for lean Composer installs and release workflow

- Exclude dev files (tests, CI, examples, IDE configs) from Composer package
- Add GitHub Actions workflow to create releases on version tags (v*)

Author: Brentjes

.gitattributes

@@ -0,0 +1,14 @@
+# Export ignore — these files are excluded from the Composer package
+# (when installed via `composer require`, users won't get these)
+
+/.github            export-ignore
+/.php-cs-fixer.dist.php export-ignore
+/.cursorrules       export-ignore
+/.gitattributes     export-ignore
+/.gitignore         export-ignore
+/CLAUDE.md          export-ignore
+/examples           export-ignore
+/llms.txt           export-ignore
+/phpstan.neon       export-ignore
+/phpunit.xml        export-ignore
+/tests              export-ignore

.github/workflows/release.yml

@@ -0,0 +1,23 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - 'v*'
+
+permissions:
+  contents: write
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    name: Create Release
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Create GitHub Release
+        uses: softprops/action-gh-release@v2
+        with:
+          generate_release_notes: true