fix(underlag): a verifikat a customer invoice points at is backed by it; PS follows the invoice link (#2298) (#2347)

* fix(underlag): a verifikat a customer invoice points at is backed by it; PS follows the invoice link (#2298)

The invoice-to-verifikat link is written on the invoice side only
(invoices.journal_entry_id, invoice_payments.journal_entry_id), while the
missing-underlag predicate and the periodisk sammanstallning resolved the
invoice from the entry's own source columns. A SIE-imported sale matched to
its invoice afterwards therefore kept warning "Underlag saknas" and was left
out of the EU sales list, although the account-based momsdeklaration showed
it and the verifikat page already listed the invoice as its underlag.

- verifikat_without_documents / transactions_without_documents: customer-
  invoice hanvisning arm (BFL 5 kap 7 §), tenant-scoped on the link row;
  new migration 20260906135702, pinned by a pg-real test.
- getInvoiceReferencesForJournalEntries(): one TS mirror of that arm, used
  by the journal-list filter and bulk exempt, /api/documents/counts (new
  invoice_references map) and the transactions list; the push cron mirrors
  it with its global reads.
- Journal list: no "Underlag saknas" chip for a covered entry, matching
  the engine's own invoice rows and the verifikat detail page.
- Periodisk sammanstallning: entries fetched by their EU-revenue lines and
  attributed through every link (engine source_id, invoices.journal_entry_id,
  invoice_payments.journal_entry_id); kontantmetod invoice_cash_payment
  entries are filed too, which the old source_type filter dropped.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019SaJfqNi4VmsG8FMKq99G6

* fix(underlag): issued invoices only, blocking mixed-customer settlements in PS, chunk-level degrade (#2298 review)

- The customer-invoice hanvisning arms (RPCs, both TS resolvers, push cron)
  now require an ISSUED invoice: status not in ('draft', 'cancelled'), the
  schema's own definition (migration 20260427150000). NON_ISSUED_INVOICE_
  STATUSES in lib/invoices/matchable-statuses.ts is the shared constant; the
  pg test pins a draft-linked and a cancelled-payment entry as still missing.
- Periodisk sammanstallning: one verifikat linked to invoices of different
  customers is no longer attributed to the first invoice; it is left out of
  the accumulators and reported once as a blocking MIXED_CUSTOMER_SETTLEMENT
  naming the voucher, the customer count and the amount. Same-customer
  settlements are filed in full.
- Transactions list: a failed invoice-reference lookup leaves that chunk's
  verdict unknown (no badges) and continues with the remaining chunks instead
  of abandoning them.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

---------

Co-authored-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com>
Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>

lib/transactions/underlag-status.ts

@@ -5,8 +5,9 @@ import { NEEDS_DOC_SOURCE_TYPES } from '@/lib/worklist/categories'
  *
  * - 'has'    : the verifikation has at least one current-version document,
  *               or is referenced by a supplier invoice whose source document
- *               is retained (BFL 5 kap 7 §: hänvisning till underlag);
- *               callers merge both kinds of ids into jeIdsWithDocs
+ *               is retained, or a customer invoice points at it (BFL 5 kap
+ *               7 §: hänvisning till underlag); callers merge all three kinds
+ *               of ids into jeIdsWithDocs
  * - 'missing': the verifikation's source type requires underlag (BFL 5 kap
  *               7§), has none, and is not exempted via journal_entry_no_doc_required
  * - 'none'   : no statement either way (system-generated source types,