fix(bookkeeping): resolve settlement account in all categorization flows and ship mis-booking audit (#1383)

Completes the #985/#986/#987 caller sweep: categorize-core, v1
batch-categorize, pending-operation edits and the MCP categorize path now
resolve the settlement leg from the transaction's cash account instead of
inheriting a hardcoded or stale account. Extends the correct_entry preview
with currency, tax and dimension line metadata so staged corrections
preserve full line fidelity. Adds a read-only audit query and a runbook for
reviewing and correcting historical mis-bookings via staged storno with
explicit approval; no automated bulk mutation.

Fixes #1001

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

lib/transactions/__tests__/categorize-core.bulk.test.ts

@@ -247,6 +247,43 @@ describe('bulkBookMatchedInboxItems: booking', () => {
     )
   })
 
+  it('books against the linked cash account instead of the 1930 mapping default', async () => {
+    const supabase = queuedSupabase([
+      { data: { id: 'i1', matched_transaction_id: 'tx-1', created_journal_entry_id: null, created_supplier_invoice_id: null } },
+      {
+        data: {
+          id: 'tx-1',
+          date: '2026-06-01',
+          amount: -700.28,
+          currency: 'SEK',
+          cash_account_id: 'cash-1',
+          journal_entry_id: null,
+        },
+      },
+      { data: { entity_type: 'aktiebolag', fiscal_year_start_month: 1 } },
+      { data: { ledger_account: '1931' } },
+      { data: [{ id: 'fp-1' }] },
+      { error: null },
+      { data: [] },
+    ])
+
+    const { booked, skipped } = await bulkBookMatchedInboxItems(supabase, 'u1', 'c1', {
+      item_ids: ['i1'],
+      category: 'expense_software',
+    })
+
+    expect(skipped).toEqual([])
+    expect(booked).toHaveLength(1)
+    expect(mockCreateJE).toHaveBeenCalledWith(
+      expect.anything(),
+      'c1',
+      'u1',
+      expect.objectContaining({ id: 'tx-1', cash_account_id: 'cash-1' }),
+      expect.objectContaining({ debit_account: '5420', credit_account: '1931' }),
+      undefined,
+    )
+  })
+
   it('forwards the shared dimensions bag onto every booked mapping result', async () => {
     // Fresh mapping object per call: the core mutates it in place, and a
     // shared fixture would leak dimensions across tests.

lib/transactions/categorize-core.ts

@@ -24,6 +24,8 @@
 import type { SupabaseClient } from '@supabase/supabase-js'
 import { eventBus } from '@/lib/events'
 import { buildMappingResultFromCategory } from '@/lib/bookkeeping/category-mapping'
+import { applySettlementAccount } from '@/lib/bookkeeping/mapping-engine'
+import { resolveSettlementAccount } from '@/lib/bookkeeping/settlement-account'
 import { createTransactionJournalEntry } from '@/lib/bookkeeping/transaction-entries'
 import { upsertCounterpartyTemplate } from '@/lib/bookkeeping/counterparty-templates'
 import { isBookkeepingError } from '@/lib/bookkeeping/errors'
@@ -329,9 +331,16 @@ export async function categorizeMatchedTransaction(
   const entityType: EntityType = (settings?.entity_type as EntityType) || 'enskild_firma'
   const fiscalYearStartMonth = settings?.fiscal_year_start_month ?? 1
 
-  const mappingResult = buildMappingResultFromCategory(
+  let mappingResult = buildMappingResultFromCategory(
     category, transaction as Transaction, isBusiness, entityType, vatTreatment, vatAmount
   )
+  const settlementAccount = await resolveSettlementAccount(
+    supabase,
+    companyId,
+    transaction.cash_account_id,
+    log,
+  )
+  mappingResult = applySettlementAccount(mappingResult, settlementAccount)
   // Dimensions PR7: tag the business lines of the generated verifikat.
   if (dimensions && Object.keys(dimensions).length > 0) {
     mappingResult.dimensions = dimensions