fix(release): repack the zip root-level for the Composer registry; make release steps idempotent

Gitea's registry answered 400 'composer.json file is missing' for the shopware-cli zip
(single top-level folder). Repack the same prebuilt content with composer.json at the root.
Drop the tag-exists skip guard so a half-finished release can be re-run; reuse an existing
release/asset. Bump to 0.1.1.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -7,6 +7,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.1.1] - 2026-10-04
+
+### Fixed
+
+- Release pipeline: the Composer registry rejected the packaged zip (`composer.json file is missing`) because `shopware-cli` zips wrap everything in a top-level folder. The same prebuilt content is now repacked root-level for the registry upload.
+- Release steps are idempotent (existing release and asset are reused, registry 409 counts as published) and the "tag exists -> skip" guard is gone, so a failed release can be re-run to completion.
+
 ## [0.1.0] - 2026-10-03
 
 ### Changed