Fuzz and validation

Fuzz/property smoke tests feed broad byte ranges into decoders and parsers.

They are good at finding:

panics
unchecked indexing
length overflows
non-canonical re-encoding

They are not a replacement for official conformance. Use fuzzing together with golden fixtures, stack tests, trace replay, and hardware evidence.

Local commands

make fuzz-smoke
make trace-replay-demo

Adding a new failure as evidence

Reduce the failing input to the smallest useful fixture.
Add a unit, property, or replay test that fails without the fix.
Document the expected behavior in the relevant tutorial/reference chapter.
Run make verify.