Update existing VX providers to the latest standards: provider.star as single source of truth,
top-level variables for metadata (name = "..."), object-style ctx access (ctx.platform.os),
stdlib helpers (make_fetch_versions, github_asset_url, env_prepend), and required path query
functions (store_root, get_execute_path, post_install). Add package_alias for PyPI/npm tools
(RFC 0033: vx meson = vx uvx:meson, vx vite = vx npx:vite). All providers must follow the
current provider.star format with proper system_install {"strategies": [...]} structure.