fix(import): show "created on import" as the mapping target for source accounts the chart lacks (#2342)

The guided Fortnox import self-mapped a source account that exists in
neither the company chart nor BAS (4599) and then rendered its Malkonto
select blank, because the dropdown only knew chart + BAS accounts. The
row looked unmapped and unmappable while the import created the account
correctly. A nameless account (referenced by #TRANS without #KONTO) was
worse: the mapper refused the self-map, so it stayed unmapped with no
self-target to pick.

- account-mapper: the bas_range self-map no longer requires a #KONTO
  name; unmapped now means exactly "outside 1000-8999". isValidBASRange
  exported as the auto-create boundary.
- AccountMappingStep (shared by both wizards): a target the list cannot
  name is an explicit "<nr> <name> (skapas vid importen)" option, a
  "nya konton skapas" badge/filter lists them, out-of-range accounts
  that block Continue are named, nameless sources say so.
- sie-import: skippedVouchers.unmappedAccounts (per account, voucher
  count) via summarizeUnmappedSkips; warning names the accounts.
- Migration result step: names created accounts and the accounts behind
  "med ej kopplade konton".

Closes #2212


Claude-Session: https://claude.ai/code/session_019SaJfqNi4VmsG8FMKq99G6

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

lib/import/__tests__/account-mapper.test.ts

@@ -108,6 +108,20 @@ describe('suggestMappings', () => {
     expect(result[0].matchType).toBe('bas_range')
   })
 
+  // Issue #2212: an account referenced only by #TRANS/#IB arrives without a
+  // #KONTO name. Refusing the self-map left it unmapped with no self-target to
+  // pick, while the parser had already promised it would be created.
+  it('self-maps a nameless in-range account (referenced without #KONTO)', () => {
+    const source = [makeSIEAccount('4599', '')]
+    const result = suggestMappings(source, basAccounts)
+
+    expect(result).toHaveLength(1)
+    expect(result[0].targetAccount).toBe('4599')
+    expect(result[0].targetName).toBe('')
+    expect(result[0].matchType).toBe('bas_range')
+    expect(result[0].confidence).toBe(0.7)
+  })
+
   it('does not self-map accounts outside BAS range (9000+)', () => {
     const source = [makeSIEAccount('9100', 'Internt konto')]
     const result = suggestMappings(source, basAccounts)

lib/import/__tests__/sie-import.test.ts

@@ -6,6 +6,7 @@ import {
   ensureFiscalPeriod,
   precheckFiscalPeriod,
   importVouchers,
+  summarizeUnmappedSkips,
   computeVoucherNumberRanges,
   linkOpeningBalanceEntryToPeriod,
   companyHasPriorActivity,
@@ -1845,3 +1846,25 @@ describe('precheckFiscalPeriod', () => {
     ).rejects.toThrow(precheck.verdict === 'conflict' ? precheck.message : 'unreachable')
   })
 })
+
+describe('summarizeUnmappedSkips', () => {
+  // Issue #2212: the result step must name WHICH accounts excluded vouchers,
+  // not just how many vouchers were excluded.
+  it('counts vouchers per unmapped account, most excluded first', () => {
+    const summary = summarizeUnmappedSkips([
+      { reason: 'unmapped', unmappedAccounts: ['0099'] },
+      { reason: 'unmapped', unmappedAccounts: ['0099', '9100'] },
+      { reason: 'unmapped', unmappedAccounts: ['9100', '9100'] },
+      { reason: 'unbalanced' },
+      { reason: 'single_line', unmappedAccounts: ['0099'] },
+    ])
+    expect(summary).toEqual([
+      { account: '0099', vouchers: 2 },
+      { account: '9100', vouchers: 2 },
+    ])
+  })
+
+  it('is empty when nothing was skipped for a missing mapping', () => {
+    expect(summarizeUnmappedSkips([{ reason: 'empty' }])).toEqual([])
+  })
+})