Replace inline sed/jq commands in release workflow with tools/update_versions.py script that:
- Updates MCPForUnity/package.json, manifest.json, Server/pyproject.toml
- Updates version references in Server/README.md, README.md, docs/i18n/README-zh.md
- Supports --dry-run and --version flags
- Auto-detects version from package.json if not specified
- Provides better error handling and progress output
Marcus Sanatan