Add PureXML.parse(bytes:) and events(bytes:) for raw [UInt8] input. The encoding
is detected following the XML sniff order (BOM first, then the <? byte pattern,
defaulting to UTF-8) and decoded with the Swift standard library only, so the
package stays Foundation-free and portable. UTF-8 and UTF-16 (both byte orders,
with or without a BOM) are supported, the encoding set the XML spec requires.
Malformed input (odd-length UTF-16) raises ParseError.malformedEncoding.
PureXML.Parsing.InputEncoding.detect(_:) exposes the detector. The lint rule
optional_data_string_conversion is disabled because its suggested fix is a
Foundation API this package cannot use. Reimplemented from the documented XML
byte-detection algorithm; no upstream code copied.
