521f437072
Visma and Fortnox migrations now carry each invoice's source voucher reference, and after the invoice steps a core linker resolves it against the SIE-imported ledger (voucher-ref resolver by date, corroborated by the 244x credit / 151x debit amount, posted only, unreferenced only) and writes registration_journal_entry_id / journal_entry_id. Anything ambiguous, mismatched or unresolved is reported and left NULL; journal entries are never written. The arcim-migration /reconcile endpoint can relink already-migrated companies. Payment vouchers are PR B. Refs #1463