Function format_file_block 

pub fn format_file_block(path: &str, content: &str) -> String

Formats a file’s content as a markdown code block.

Arguments

• path - The file path (used for display and language detection)
• content - The file contents

Returns

A markdown-formatted string with the file header and code fence

Format

## File: {path}
```{lang}
{content}
```