As a content creator, if I enter invalid YAML, I want to see clear error messages that help me identify and fix the issue so that I can correct my syntax efficiently.

This involves implementing a YAML parsing function that catches syntax errors. The errors should be displayed to the user in a clear and helpful way, ideally close to the editor itself.

Acceptance Criteria:

• When the text in the editor is not valid YAML, a user-friendly error message is displayed.

• (stretch) The error message provides context about the syntax issue (e.g., "Invalid character on line 5").

• The error message is removed automatically once the YAML becomes valid.

• The Live card preview does not attempt to render with invalid YAML data.