fix(mdxish): terminal custom component makes page crashes

[Jadenzzz]

	Fix RM-XYZ

🧰 Changes

Root cause

Terminal components from marketplace need to receive multiline string children, but the current markdown processing corrupts newlines through:

• micromark MDX tokenizer - exist in newlines in expressions, causing parse errors
• remarkBreaks - splits newlines into separate text nodes with
  tag
• rehypeRaw - normalizes \n to spaces

Current solution

• Replace newlines with a constant and collpase content into single line
• Make sure passing string instead of html nodes to component like Terminal

Describe your changes in detail.

🧬 QA & Testing

• Broken on production.
• Working in this PR app.