Function validate_file_references 

pub fn validate_file_references(
    references: &[String],
    project_dir: &Path,
) -> Result<Vec<String>>

Validate that file references exist on the filesystem.

This function takes a list of relative file paths and checks if they exist relative to the given project directory. It returns a list of missing references for error reporting.

Arguments

• references - List of relative file paths to validate
• project_dir - Base directory to resolve relative paths against

Returns

A list of references that were not found

Errors

Returns an error if the project directory cannot be accessed

Examples

let references = vec![
    ".agpm/snippets/existing.md".to_string(),
    ".agpm/snippets/missing.md".to_string(),
];

let project_dir = Path::new("/path/to/project");
let missing = validate_file_references(&references, project_dir)?;
// Returns only the missing.md entry