feat(invoices): allow BAS class 1-3 posting-account overrides and complete the aktiekapital note (#1121)

- invoice/article posting-account overrides accept active class 1-3 accounts;
  class 1-2 (balance-sheet) accounts are rejected on VAT-bearing lines so the
  ruta 05 tax base always books to a 3xxx account
- shared posting-account regex across server schemas, pending-operation
  re-validation, and client forms
- share-capital settings (aktiekapital/antal_aktier) feed the annual-report
  note; kvotvarde derived per ABL 1 kap 6 $; all-or-nothing pair constraint
- signed per-rate VAT breakdown on credit-note PDFs; U+2212 to ASCII hyphen

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

app/api/articles/__tests__/route.test.ts

@@ -131,6 +131,22 @@ describe('GET/POST /api/articles', () => {
     expect(body.data.revenue_account).toBe('3001')
   })
 
+  it('POST accepts a posting account that is active class 2 in the chart', async () => {
+    enqueue({ data: { account_class: 2, is_active: true } })
+    enqueue({ data: { id: 'a1', name: 'Deposition', article_number: '4', revenue_account: '2897' } })
+
+    const request = createMockRequest('/api/articles', {
+      method: 'POST',
+      body: { name: 'Deposition', price_excl_vat: 1000, vat_rate: 0, revenue_account: '2897' },
+    })
+
+    const response = await POST(request, { params: Promise.resolve({}) })
+    const { status, body } = await parseJsonResponse<{ data: { revenue_account: string } }>(response)
+
+    expect(status).toBe(200)
+    expect(body.data.revenue_account).toBe('2897')
+  })
+
   it('POST creates an article and auto-assigns a number', async () => {
     // 1st DB hit: insert ... returning the row (article_number still null).
     enqueue({ data: { id: 'a1', name: 'Konsulttimme', article_number: null, type: 'tjanst', vat_rate: 25 } })