Recovery during the prod outage uncovered a second mig 098 bug: §6.2
assertion '0 NULL submission_code on active+published rows' counted
the 77 orphan rules (proceeding_type_id IS NULL, cross-cutting
Wiedereinsetzung / Schriftsatznachreichung pattern) and rejected the
migration. Patch: gate the NULL count on `proceeding_type_id IS NOT
NULL` so orphans pass through. Migration already applied to prod via
manual recovery with the same patched assertion; this commit aligns
the in-repo file with the deployed state.