feat(arcim-migration): import the Fortnox asset register during migration (#1999)

The Fortnox migration now imports the asset register (GET /3/assets + /3/assets/types) as local register rows via createAsset: category from the type's anskaffningskonto BAS class, useful life from the source's depreciation window (K2 schablon fallback), never any journal entries (values arrived via SIE; the source's depreciated-to date is recorded in notes for review of the first proposal). Sold/scrapped/voided assets are skipped, re-runs dedupe, one bad asset counts as skipped. Gated behind FORTNOX_ASSET_SCOPES_APPROVED=false until the portal registration for integration 39254 carries the Assets scope, so hosted consents are unchanged and the wizard shows an honest skipped row.

Co-authored-by: pgronberg <pgronberg@users.noreply.github.com>

extensions/general/arcim-migration/__tests__/migrate-guard.test.ts

@@ -149,6 +149,52 @@ describe('POST /migrate: SIE-import-required guard', () => {
   it('allows a company-info-only run with no SIE import (writes no ledger data)', async () => {
     ;(getConsent as Mock).mockResolvedValue({ id: 'consent-1', status: 1, provider: 'fortnox' })
 
+    const res = await handler(
+      migrateRequest({
+        consentId: 'consent-1',
+        importCompanyInfo: true,
+        importCustomers: false,
+        importSuppliers: false,
+        importSalesInvoices: false,
+        importSupplierInvoices: false,
+        importAssets: false,
+      }),
+      buildCtx(0),
+    )
+
+    expect(res.status).toBe(200)
+    expect(executeMigration).toHaveBeenCalledTimes(1)
+  })
+
+  // The asset register is entity data too: its rows carry BAS account triples
+  // and depreciation plans that only mean something against an imported chart
+  // of accounts, so an assets-only run is gated like any other entity import.
+  it('blocks an assets-only run with no SIE import', async () => {
+    ;(getConsent as Mock).mockResolvedValue({ id: 'consent-1', status: 1, provider: 'fortnox' })
+
+    const res = await handler(
+      migrateRequest({
+        consentId: 'consent-1',
+        importCompanyInfo: false,
+        importCustomers: false,
+        importSuppliers: false,
+        importSalesInvoices: false,
+        importSupplierInvoices: false,
+        importAssets: true,
+      }),
+      buildCtx(0),
+    )
+
+    expect(res.status).toBe(409)
+    expect(executeMigration).not.toHaveBeenCalled()
+  })
+
+  // Backward compatibility: a client written before the asset option existed
+  // omits the field entirely. That request must behave as it did then, so the
+  // omitted option neither imports assets nor trips this guard.
+  it('allows a company-info-only run that omits importAssets entirely', async () => {
+    ;(getConsent as Mock).mockResolvedValue({ id: 'consent-1', status: 1, provider: 'fortnox' })
+
     const res = await handler(
       migrateRequest({
         consentId: 'consent-1',