feat(invoices): registrera utan att bokföra + explicit Bokför-steg (#1040)

* feat(invoices): registrera utan att bokföra + explicit Bokför-steg

Companies where one person registers supplier invoices / sends customer
invoices while ekonomi does the actual bookkeeping had no way to split
the two: under faktureringsmetoden every registration/send booked the
journal entry inline.

- New company setting defer_invoice_booking (default off, accrual only):
  registering a supplier invoice or sending/marking-sent a customer
  invoice creates NO journal entry.
- New explicit booking routes POST /api/supplier-invoices/[id]/book and
  POST /api/invoices/[id]/book: create the registration/revenue entry
  afterwards, CAS-guarded against concurrent booking (a lost race
  cancels the just-posted voucher with a gap explanation), including
  periodisering schedules.
- Detail pages show "Ej bokförd ännu" + a Bokför button for unbooked
  accrual invoices; the settings toggle lives under Bokföringsmetod.
- mark-paid needs no changes: both payment flows already route on the
  journal-entry link, so an invoice still unbooked when paid gets the
  full cash-style entry.
- The mark-sent fail-closed rollback now keys on the same gate so
  deferred sends are not rolled back as booking failures.

Fixes #967

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

* fix(invoices): harden deferred booking after review

CodeRabbit round on #1040:
- CAS link guards also require a still-bookable status (and uncredited,
  customer side) so a concurrent mark-paid/credit cannot end up with a
  double-posting registration/revenue entry.
- Settings reads fail closed instead of defaulting to accrual rules.
- Detail pages surface the ACCRUAL_SCHEDULE_FAILED warning instead of
  showing plain success, and the customer page no longer stringifies
  structured errors into "[object Object]".
- The settings form normalizes defer_invoice_booking to false under
  kontantmetoden so a stale flag cannot re-activate on method switch.

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

---------

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

lib/bookkeeping/__tests__/booking-mode.test.ts

@@ -0,0 +1,24 @@
+import { describe, it, expect } from 'vitest'
+import { booksInvoicesOnIssue } from '../booking-mode'
+
+describe('booksInvoicesOnIssue (#967)', () => {
+  it('books at issue for accrual companies by default', () => {
+    expect(booksInvoicesOnIssue({ accounting_method: 'accrual' })).toBe(true)
+    expect(booksInvoicesOnIssue({ accounting_method: 'accrual', defer_invoice_booking: false })).toBe(true)
+  })
+
+  it('defers when defer_invoice_booking is on', () => {
+    expect(booksInvoicesOnIssue({ accounting_method: 'accrual', defer_invoice_booking: true })).toBe(false)
+  })
+
+  it('never books at issue under the cash method, regardless of the flag', () => {
+    expect(booksInvoicesOnIssue({ accounting_method: 'cash' })).toBe(false)
+    expect(booksInvoicesOnIssue({ accounting_method: 'cash', defer_invoice_booking: true })).toBe(false)
+  })
+
+  it('treats missing settings as the historical accrual default', () => {
+    expect(booksInvoicesOnIssue(null)).toBe(true)
+    expect(booksInvoicesOnIssue(undefined)).toBe(true)
+    expect(booksInvoicesOnIssue({})).toBe(true)
+  })
+})

lib/bookkeeping/booking-mode.ts

@@ -0,0 +1,24 @@
+/**
+ * #967 "Registrera men bokför inte": whether issuing an invoice (registering
+ * a supplier invoice, sending a customer invoice) books it inline.
+ *
+ * Inline booking happens only under faktureringsmetoden (accrual) with
+ * defer_invoice_booking off. Kontantmetoden companies never book at issue
+ * (they book at payment), and deferred companies book via the explicit
+ * "Bokför" routes (POST /api/supplier-invoices/[id]/book,
+ * POST /api/invoices/[id]/book) instead.
+ *
+ * The payment flows need no gate of their own: both mark-paid paths already
+ * route on whether a live journal-entry link exists, so an invoice that is
+ * still unbooked when paid gets the full cash-style entry at payment.
+ */
+export function booksInvoicesOnIssue(
+  settings:
+    | { accounting_method?: string | null; defer_invoice_booking?: boolean | null }
+    | null
+    | undefined
+): boolean {
+  // No settings row: match the historical default (accrual, book at issue).
+  if (!settings) return true
+  return (settings.accounting_method || 'accrual') === 'accrual' && !settings.defer_invoice_booking
+}