fix: handle existing releases when creating with artifacts

[thoroc]

Problem\nThe workflow failed because release v0.4.5 already existed from a previous failed run, causing gh release create to fail with "a release with the same tag name already exists".\n\n## Solution\nAdded logic to check if a release already exists and delete it before recreating with all artifacts:\n\nbash\nif gh release view "${TAG}" &>/dev/null; then\n echo "Release ${TAG} already exists, deleting it to recreate with artifacts..."\n gh release delete "${TAG}" --yes\nfi\n\n\nThis ensures the release is atomic with all artifacts, handling retries and failed partial runs gracefully.

[github-actions]

@github-copilot Please review this PR focusing on:

1. Code quality, best practices, and potential bugs
2. Security vulnerabilities and unsafe patterns
3. Performance implications
4. Documentation accuracy and completeness
5. Test coverage and edge cases

Please provide specific, actionable feedback.