Use one marshal surrogatepass decoder for PYZ directories and Python bytecode.
Validate ordinary UTF-8 spans with the native fatal decoder, preserving BOMs,
lone surrogates, raw bytes and marshal reference slots.
Distinguish legacy full-pyc CArchive modules from modern marshal-only modules
before reconstructing headers. Share typed source/codec failures between stream
output and completion while retaining native-read drain and cleanup ownership.
Validated focused producer, reader, lifecycle, CLI and MCP regressions, plus
public inventory/extraction of CPython 3.14-generated marshal tables and code.
No packaged application was executed. Document original versus derived bytes.
Fixes#6800Fixes#6789
morluto