Recreate and explain the error

Some shells escape "!" to "\!" even in single-quoted strings, causing
the markdown image reference parser to fail to recognize the ![alt](path)
syntax. The entire escaped string was then treated as a file path,
producing the error "image file not found: \![alt text](path)".

Strip the leading backslash when the input starts with \![ before
attempting to parse as a markdown image reference.

https://claude.ai/code/session_01BqcPiZ39GE4j4ZhvHVFyZ8