Patch Changes

• #17460 3b93a1a Thanks @astrobot-houston! - Fixes custom transform functions being dropped when a tag or node also specifies a custom render component. User-written transforms are now always preserved; only Markdoc's built-in transforms are removed so the custom component wins.

• #17191 fc3fb2b Thanks @eldardada! - Fixes custom transform functions being incorrectly dropped for tags and nodes whose names require bracket access (e.g. side-note). The check that detects whether a transform respects a custom render component now recognizes bracket notation, optional chaining and whitespace, not only dot notation.