Mig 134's step 4 UPDATEs paliad.deadline_rules to reassign 16 rules
to the unified upc.apl.unified proceeding_type. The mig-079 audit
trigger requires set_config('paliad.audit_reason', …, true) before
any mutation — mig 134 missed it, causing the migration runner to
abort with P0001 "audit reason required for UPDATE" on every boot
after #130 landed.
Adds the canonical set_config call at the top of both up + down,
matching the pattern from mig 082, 099, 100, 103, 106, 110, 127, 129.