U+0085 (NEL), U+2028 (LINE SEPARATOR), and U+2029 (PARAGRAPH SEPARATOR)
are treated as line terminators by some log shippers and by JS's own
lexical grammar (and are not escaped by JSON.stringify by default), so
they could still be used to forge audit log entries even after the
initial C0/DEL fix. logSafe now strips all five categories.
Prevents audit log injection: subjectId, tenantId, and reason trace back
to request input, so an unsanitized newline could forge a second,
fully-formed audit line indistinguishable from a real entry. Adds
logSafe() to strip control characters before interpolation and logs the
previously-missing policy field.