/// Converts a file size in bytes into a human-readable format.
///
/// This function formats byte sizes dynamically into **KB, MB, or GB** for readability.
///
/// # Conversion Logic:
/// - **1,024 bytes → KB**
/// - **1,024 KB → MB**
/// - **1,024 MB → GB**
///
/// # Formatting:
/// - Uses **two decimal places** for precision (e.g., `"10.43 MB"`).
/// - If size is below 1 KB, it is displayed in **raw bytes** (e.g., `"512 bytes"`).
///
/// # Parameters:
/// - `bytes`: The size in bytes to format.
///
/// # Returns:
/// - A `String` representing the human-readable file size.