Validate XML bytes before shared syntax parsing so literal U+FFFD remains valid while malformed bytes and declaration mismatches fail at their producing boundary.
Validation: 92 focused checks, 3 selected fake Apktool boundary checks, 6 final encoding controls, check:fast and docs:check. Ghidra coverage uses tiny real files and descriptors, without a real engine or Windows qualification.
Refs #4712
morluto