The privacy.redact_pii config reader on line 1546 used bare 'yaml'
which is not in scope — yaml is imported as '_yaml' at module level
(line 93) and as '_y' in other methods. The NameError was silently
caught by the try/except, so PII redaction never activated even when
configured.
Add a local 'import yaml as _pii_yaml' consistent with the pattern
used elsewhere in the file.
7c9beb5829