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>

lib/invoices/__tests__/pdf-template-amounts.test.ts

@@ -0,0 +1,68 @@
+import { describe, expect, it } from 'vitest'
+import type { InvoiceItem } from '@/types'
+import { buildPdfVatBreakdown, formatPdfCurrency } from '@/lib/invoices/pdf-template'
+
+function makeItem(overrides: Partial<InvoiceItem> = {}): InvoiceItem {
+  return {
+    id: 'item-1',
+    invoice_id: 'invoice-1',
+    sort_order: 0,
+    line_type: 'product',
+    description: 'Invoice row',
+    quantity: 1,
+    unit: 'st',
+    unit_price: 100,
+    line_total: 100,
+    vat_rate: 25,
+    vat_amount: 25,
+    ...overrides,
+  }
+}
+
+describe('formatPdfCurrency', () => {
+  it('uses a PDF-safe minus for Swedish negative amounts', () => {
+    const formatted = formatPdfCurrency(-12.34, 'SEK', 'sv')
+
+    expect(formatted).toBe('-12,34 SEK')
+    expect(formatted).not.toContain('\u2212')
+  })
+
+  it('preserves English negative amount formatting', () => {
+    expect(formatPdfCurrency(-12.34, 'SEK', 'en')).toBe('-12.34 SEK')
+  })
+
+  it('does not change positive Swedish amount formatting', () => {
+    expect(formatPdfCurrency(18_992.2, 'SEK', 'sv')).toBe('18\u00a0992,20 SEK')
+  })
+})
+
+describe('buildPdfVatBreakdown', () => {
+  it('subtracts a negative adjustment from its VAT group', () => {
+    const breakdown = buildPdfVatBreakdown([
+      makeItem({ id: 'sale', line_total: 100, vat_amount: 25 }),
+      makeItem({ id: 'deduction', line_total: -12.34, vat_amount: -3.09 }),
+    ])
+
+    expect(breakdown.get(25)).toEqual({ base: 87.66, vat: 21.91 })
+  })
+
+  it('keeps whole credit-note VAT groups negative', () => {
+    const breakdown = buildPdfVatBreakdown([
+      makeItem({ line_total: -100, vat_amount: -25 }),
+    ])
+
+    expect(breakdown.get(25)).toEqual({ base: -100, vat: -25 })
+  })
+
+  it('keeps mixed VAT rates signed and excludes text rows', () => {
+    const breakdown = buildPdfVatBreakdown([
+      makeItem({ id: 'rate-25', line_total: 200, vat_rate: 25, vat_amount: 50 }),
+      makeItem({ id: 'rate-12', line_total: 100, vat_rate: 12, vat_amount: 12 }),
+      makeItem({ id: 'rate-12-deduction', line_total: -20, vat_rate: 12, vat_amount: -2.4 }),
+      makeItem({ id: 'text', line_type: 'text', line_total: 999, vat_rate: 25, vat_amount: 999 }),
+    ])
+
+    expect(breakdown.get(25)).toEqual({ base: 200, vat: 50 })
+    expect(breakdown.get(12)).toEqual({ base: 80, vat: 9.6 })
+  })
+})