feat(vat): book the momsrapport as an editable settlement verifikat (#980) (#983)

* feat(vat): book the momsrapport as an editable settlement verifikat (#980)

Adds a "Bokfor momsrapporten" card under the VAT declaration that builds
an editable verifikat proposal from the report and books it through the
ordinary journal entry form:

- lib/reports/vat-settlement.ts: proposal builder. Clears each 26xx
  account at exact ore, books the net on 2650 (att betala) or 1650 (att
  aterfa) at the filed whole-krona amount (buildFiledAmounts, oretal
  faller bort per SFL 22 kap 1 par), balances the gap on 3740. Surfaces
  existing vat_settlement entries in the period so the UI can warn
  before a double booking.
- GET /api/reports/vat-declaration/settlement-proposal: same period
  params as the sibling report routes.
- VatBookingCard (reports view): fetches the proposal, warns when the
  period already has a posted settlement or draft, and opens the
  JournalEntryForm (bare, prefilled, source_type vat_settlement) in a
  dialog so every line is editable before committing. Booking uses the
  existing engine path: balance validation, period locks, voucher
  series per source type.
- vat_settlement entries are excluded from the declaration projection
  (calculateVatDeclaration via new shared fetchVatAccountTotals, and
  the MCP computeVatReport for parity): a pure-projection report would
  otherwise read zero, and a later Skatteverket submission would file
  zeros, the moment the settlement is booked.

No migration needed: the vat_settlement source type shipped in
20260708100000.

Closes #980

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(vat): block re-booking a settled period, fail loud on lookup errors (CodeRabbit)

The proposal is not delta-aware (it re-clears the FULL period), so a
second booking while a posted settlement exists would corrupt the 26xx
balances: disable "Skapa verifikat" until that verifikat is annulled
(storno restores the balances). And since the existing-settlement
lookup now gates that button, a swallowed query error would silently
re-enable it: throw instead.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

extensions/general/mcp-server/__tests__/vat-report-compute.test.ts

@@ -26,6 +26,7 @@ function mockSupabaseWithLines(lines: MockLine[]) {
   chain.range = () => terminal
   chain.lte = () => chain
   chain.gte = () => chain
+  chain.neq = () => chain
   chain.in = () => chain
   chain.eq = () => chain
   chain.select = () => chain

extensions/general/mcp-server/server.ts

@@ -1081,6 +1081,10 @@ export async function computeVatReport(
       .select('account_number, debit_amount, credit_amount, journal_entries!inner(entry_date, status, user_id)')
       .eq('journal_entries.company_id', companyId)
       .in('journal_entries.status', ['posted', 'reversed'])
+      // Momsredovisning entries (the settlement verifikat clearing 26xx to
+      // 2650/1650) would zero the rutor once booked; exclude them so this
+      // report matches lib/reports/vat-declaration.ts (fetchVatAccountTotals).
+      .neq('journal_entries.source_type', 'vat_settlement')
       .gte('journal_entries.entry_date', startDate)
       .lte('journal_entries.entry_date', endDate)
       .range(from, to)