Function validate_package_name 

pub fn validate_package_name<'a>(
    name: &'a str,
    config: Option<&ValidationConfig>,
) -> Result<&'a str>

What: Validate a package name according to Arch Linux packaging standards.

Inputs:

• name: Package name to validate
• config: Optional validation configuration (uses defaults if None)

Output:

• Result<&str> containing the validated name, or an error

Details:

• Validates against PKGBUILD naming rules:
  • Allowed characters: lowercase letters (a-z), digits (0-9), @, ., _, +, -
  • Cannot start with hyphen (-) or period (.)
  • Must be non-empty
  • Maximum length: 127 characters (default, configurable)
• Returns the input string on success for method chaining

Errors

• Returns Err(ArchToolkitError::EmptyInput) if name is empty and strict mode is enabled
• Returns Err(ArchToolkitError::InvalidPackageName) if name contains invalid characters
• Returns Err(ArchToolkitError::InputTooLong) if name exceeds maximum length