fix(vat,documents): EU reverse-charge packs feed ruta 20/21; daily reanchor cron for floating supplier-invoice underlag (#2095)

Two user reports (Anders, 2026-08-25 + 2026-08-29):

1. The seeded standardmallar "Inkop EU-varor/-tjanster, omvand moms 25%"
   booked the cost on 4010/6540, which no momsdeklaration ruta reads, so the
   fiktiv moms filled ruta 30/48 while ruta 20/21 (inkopsvarde) stayed 0;
   Skatteverket rejects that (FK004, ML 13 kap). The packs now book directly
   on the basis accounts 4515/4535 (ACCOUNT_RUTA -> ruta 20/21); the
   transaction-picker path already skips its own basis emission for basis
   debit accounts, so no double counting. Regression test pins every
   reverse-charge pack to a 44xx/45xx business debit. Prod rows update via
   the existing pack sync cron (upsert on pack_slug).

2. A kontantmetod payment verifikat stayed "Underlag saknas" although the
   invoice PDF was attached and eligible on every static condition: the
   inline anchorSupplierInvoiceDocument silently did nothing (prod case
   2026-08-28, verified in audit_log: no document_attachments update between
   the payment booking and the user's manual re-upload). The helper now
   verifies the guarded update actually matched a row instead of claiming
   success on zero rows, logs its silent bail branches, and a new daily cron
   (/api/documents/reanchor/cron) re-runs the anchor for any floating
   retained document with a posted verifikat, replacing the pattern of
   one-off repair migrations (20260727180000, 20260824150000). The sweep
   names the FK in its embed and is idempotent; locked/closed periods are
   skipped as before.


Claude-Session: https://claude.ai/code/session_01Jj6Rg1ViyFRej55gbxLVgj

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

lib/core/documents/__tests__/supplier-invoice-underlag.test.ts

@@ -4,6 +4,7 @@ import { createQueuedMockSupabase } from '@/tests/helpers'
 import {
   anchorSupplierInvoiceDocument,
   reanchorOrphanedSupplierInvoiceDocuments,
+  sweepFloatingSupplierInvoiceDocuments,
 } from '../supplier-invoice-underlag'
 
 /**
@@ -45,7 +46,7 @@ describe('anchorSupplierInvoiceDocument', () => {
           { id: 'je-pay', status: 'posted', fiscal_period: openPeriod },
         ],
       },
-      { data: null },
+      { data: [{ id: 'doc-1' }] },
     ])
 
     const anchored = await anchorSupplierInvoiceDocument(
@@ -77,7 +78,7 @@ describe('anchorSupplierInvoiceDocument', () => {
           { id: 'je-pay', status: 'posted', fiscal_period: openPeriod },
         ],
       },
-      { data: null },
+      { data: [{ id: 'doc-1' }] },
     ])
 
     expect(
@@ -108,7 +109,7 @@ describe('anchorSupplierInvoiceDocument', () => {
           { id: 'je-p2', status: 'posted', fiscal_period: openPeriod },
         ],
       },
-      { data: null },
+      { data: [{ id: 'doc-1' }] },
     ])
 
     expect(
@@ -227,6 +228,32 @@ describe('anchorSupplierInvoiceDocument', () => {
     expect(supabase.from).toHaveBeenCalledTimes(1)
   })
 
+  it('reports a zero-row update as null: a write that never happened is not an anchor', async () => {
+    // Prod case 2026-08-28 (faktura 118776): every static condition passed yet
+    // the document stayed floating. The guarded update can match nothing (a
+    // concurrent writer, or RLS filtering the row); claiming success then hides
+    // the miss from both callers and the reconcile cron.
+    const { supabase, enqueueMany } = createQueuedMockSupabase()
+    enqueueMany([
+      {
+        data: {
+          id: 'si-1',
+          document_id: 'doc-1',
+          registration_journal_entry_id: null,
+          payment_journal_entry_id: 'je-pay',
+        },
+      },
+      { data: { id: 'doc-1', journal_entry_id: null, is_current_version: true } },
+      { data: [] },
+      { data: [{ id: 'je-pay', status: 'posted', fiscal_period: openPeriod }] },
+      { data: [] }, // UPDATE matched no rows
+    ])
+
+    await expect(
+      anchorSupplierInvoiceDocument(supabase as unknown as SupabaseClient, 'company-1', 'si-1'),
+    ).resolves.toBeNull()
+  })
+
   it('reports failure as null instead of throwing at the caller', async () => {
     const { supabase, enqueueMany } = createQueuedMockSupabase()
     enqueueMany([
@@ -250,6 +277,63 @@ describe('anchorSupplierInvoiceDocument', () => {
   })
 })
 
+describe('sweepFloatingSupplierInvoiceDocuments', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  const openPeriod = { is_closed: false, locked_at: null }
+
+  it('anchors every floating retained document it finds, across companies', async () => {
+    const { supabase, enqueueMany } = createQueuedMockSupabase()
+    enqueueMany([
+      // Candidate scan: two invoices with floating current-version documents.
+      {
+        data: [
+          { id: 'si-1', company_id: 'company-1', document: { id: 'doc-1', journal_entry_id: null, is_current_version: true } },
+          { id: 'si-2', company_id: 'company-2', document: { id: 'doc-2', journal_entry_id: null, is_current_version: true } },
+        ],
+      },
+      // anchorSupplierInvoiceDocument for si-1 (5 queries)
+      { data: { id: 'si-1', document_id: 'doc-1', registration_journal_entry_id: null, payment_journal_entry_id: 'je-1' } },
+      { data: { id: 'doc-1', journal_entry_id: null, is_current_version: true } },
+      { data: [] },
+      { data: [{ id: 'je-1', status: 'posted', fiscal_period: openPeriod }] },
+      { data: [{ id: 'doc-1' }] },
+      // anchorSupplierInvoiceDocument for si-2: its only verifikat is locked.
+      { data: { id: 'si-2', document_id: 'doc-2', registration_journal_entry_id: null, payment_journal_entry_id: 'je-2' } },
+      { data: { id: 'doc-2', journal_entry_id: null, is_current_version: true } },
+      { data: [] },
+      { data: [{ id: 'je-2', status: 'posted', fiscal_period: { is_closed: true, locked_at: null } }] },
+    ])
+
+    const result = await sweepFloatingSupplierInvoiceDocuments(
+      supabase as unknown as SupabaseClient,
+    )
+    expect(result).toEqual({ candidates: 2, anchored: 1 })
+  })
+
+  it('returns zeros and touches nothing when no document is floating', async () => {
+    const { supabase, enqueueMany } = createQueuedMockSupabase()
+    enqueueMany([{ data: [] }])
+
+    const result = await sweepFloatingSupplierInvoiceDocuments(
+      supabase as unknown as SupabaseClient,
+    )
+    expect(result).toEqual({ candidates: 0, anchored: 0 })
+    expect(supabase.from).toHaveBeenCalledTimes(1)
+  })
+
+  it('survives a failed candidate scan without throwing', async () => {
+    const { supabase, enqueueMany } = createQueuedMockSupabase()
+    enqueueMany([{ error: { message: 'relation walk failed' } }])
+
+    await expect(
+      sweepFloatingSupplierInvoiceDocuments(supabase as unknown as SupabaseClient),
+    ).resolves.toEqual({ candidates: 0, anchored: 0 })
+  })
+})
+
 describe('reanchorOrphanedSupplierInvoiceDocuments', () => {
   beforeEach(() => {
     vi.clearAllMocks()
@@ -272,7 +356,7 @@ describe('reanchorOrphanedSupplierInvoiceDocuments', () => {
       {
         data: [{ id: 'je-pay', status: 'posted', fiscal_period: { is_closed: false, locked_at: null } }],
       },
-      { data: null },
+      { data: [{ id: 'doc-1' }] },
     ])
 
     expect(