# Fastavro Avro Schema Traversal Crash

Benign local PoC for fastavro `load_schema` handling of referenced `.avsc` schemas.

Run:

```bash
reproduce.py
```

Expected success tokens:

```text
MFV_FASTAVRO_TRAVERSAL_MARKER_CONFIRMED
MFV_FASTAVRO_SIGSEGV_CONFIRMED
MFV_REPRO_OK_MFV-46
```

The PoC uses only local schema files, subprocess isolation for the crashing case, and inert string markers. It does not use shell commands, network, secrets, persistence, or destructive file operations.