Add/bokslut (#718)

* feat(arcim-migration): Briox provider with SIE-over-API import

- Briox auth via account ID + application token (no app-level
  credentials); both tokens rotate on refresh and are persisted
- New sie-fetcher pulls the general ledger as SIE through the
  provider API for Fortnox, Briox and Bjorn Lunden
- Wizard stops on a failed SIE import and surfaces the real errors
  instead of proceeding to the misleading migrate-guard message
- PROVIDER_SIE_ONLY_FORTNOX renamed to PROVIDER_SIE_NOT_SUPPORTED;
  new PROVIDER_TOKEN_INVALID for rejected provider credentials

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

* feat(bookkeeping): per-line accruals (periodisering) on invoices and supplier invoices

Defer revenue/costs per invoice line to 29xx/17xx interim accounts with
automatic monthly dissolution (nightly cron + catch-up at registration),
schedule cancellation on credit, year-end auto-detect exclusion for
already-scheduled invoices, invoice-inbox service-period extraction for
prefill, and an MCP tool to list schedules.

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

* feat(bokslut): iXBRL arsredovisning generation and Bolagsverket digital filing

Generate the annual report as iXBRL from a generated taxonomy registry
(K2 element lists, taxonomy:generate/check scripts + CI guard), expose it
via the fiscal-period API, and add the bolagsverket extension for digital
submission to eget utrymme with webhook-driven status tracking
(submissions table + pg tests, lifecycle events, year-end wizard UI).

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

* test(mcp): raise origin-guard test timeout to 20s

The dynamic import pulls in the full server module; the parse alone
flirts with the 5s default under full-suite parallel load.

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

* Add new scripts and documentation for K2 AB taxonomy generation and validation

- Introduced `generate-taxonomy-registry.ts` to automate the generation of the iXBRL taxonomy concept registry from official element lists and tuple models.
- Added `validate-ixbrl.mjs` for validating generated iXBRL reports against the official taxonomy package using Arelle.
- Included new documentation files:
  - `k2-ab-arsredovisning-elementlista-2024-09-12_rev20250312_sv.xlsx`
  - `tuple-innehallsmodell-arsredovisning-k2-2024-09-12.xlsx`
  - `taxonomi-paket-2024-09-12_rev20250312.zip`

* Add tests for bookkeeping accruals dissolution and supplier invoices

- Implement tests for the POST /api/bookkeeping/accruals/[id]/dissolve route, covering success and error scenarios.
- Add tests for the DELETE /api/supplier-invoices/[id] route, including authentication checks and validation of invoice deletion conditions.
- Introduce tests for the Arcim migration provider client, ensuring token handling and error classification.
- Create tests for the Bolagsverket extension, validating submission role enforcement and environment settings.
- Add Zod schemas for Bolagsverket response payloads to ensure proper validation.
- Implement tests for MCP server's list accrual schedules, confirming registration and scope mapping.
- Add consistency tests for IXBRL document generation, ensuring duplicate facts and XML escaping are handled correctly.
- Introduce typed domain errors for accrual schedules to improve error handling in the service.
- Add tests for resolving consent with Briox token refresh concurrency, ensuring proper token management and error handling.

* fix(tests): update payload size guard comments to reflect recent changes in tool descriptions and ceiling adjustments

* fix(gitattributes): mark generated JSON files in bokslut taxonomy as linguist-generated

* feat(migrations): add backfill for invoices.journal_entry_id and fallback for next_voucher_number user_id

* feat(bokslut): enhance compliance and financial processing features with new submission details and security measures

---------

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

types/index.ts

@@ -713,6 +713,14 @@ export interface SupplierInvoiceItem {
   // rate drives the fiktiv-moms + basbelopp booking. See the booking engine.
   reverse_charge_rate: number | null
 
+  // Periodisering (förutbetald kostnad): when set, the registration entry
+  // debits accrual_balance_account (17xx) instead of account_number, and an
+  // accrual_schedules row dissolves the net amount monthly over the period.
+  // VAT is never deferred. Both dates set together or not at all.
+  accrual_period_start?: string | null
+  accrual_period_end?: string | null
+  accrual_balance_account?: string | null
+
   created_at: string
 }
 
@@ -891,6 +899,15 @@ export interface InvoiceItem {
   article_id?: string | null
   revenue_account?: string | null
 
+  // Periodisering (förutbetald intäkt): when set, the revenue entry credits
+  // accrual_balance_account (29xx) instead of the line's revenue account, and
+  // an accrual_schedules row dissolves the net amount monthly over the
+  // period. Output VAT is never deferred. Both dates set together or not at
+  // all. Not combinable with ROT/RUT or text lines.
+  accrual_period_start?: string | null
+  accrual_period_end?: string | null
+  accrual_balance_account?: string | null
+
   // ROT/RUT-avdrag (Sweden's tax deduction for household services / home
   // renovation). When `deduction_type` is set, the system computes
   // `deduction_amount` from the rules in lib/invoices/rot-rut-rules.ts
@@ -1223,6 +1240,7 @@ export type JournalEntrySourceType =
   | 'supplier_credit_note'
   | 'currency_revaluation'
   | 'reminder_fee'
+  | 'accrual'
 
 // Journal entry status
 export type JournalEntryStatus = 'draft' | 'posted' | 'reversed' | 'cancelled'
@@ -1330,6 +1348,60 @@ export interface JournalEntryLine {
   created_at: string
 }
 
+// ── Periodisering (accrual schedules) ─────────────────────────
+// One schedule per deferred invoice line: the net amount sits on a 17xx/29xx
+// interim account and dissolves to the P&L account via monthly 'accrual'
+// entries. See lib/bookkeeping/accruals/.
+
+export type AccrualDirection = 'expense' | 'revenue'
+export type AccrualScheduleStatus = 'active' | 'completed' | 'cancelled'
+export type AccrualInstallmentStatus = 'pending' | 'posted' | 'cancelled'
+
+export interface AccrualSchedule {
+  id: string
+  user_id: string
+  company_id: string
+  direction: AccrualDirection
+  supplier_invoice_id: string | null
+  supplier_invoice_item_id: string | null
+  invoice_id: string | null
+  invoice_item_id: string | null
+  // Interim balance account (17xx for expense, 29xx for revenue) and the
+  // P&L account each installment dissolves to. Strings, like all accounts.
+  balance_account: string
+  target_account: string
+  // Net SEK amount as booked (ex VAT). Always equals the sum of installments.
+  total_amount: number
+  period_start: string
+  period_end: string
+  months: number
+  origin_journal_entry_id: string | null
+  // Dissolution entries are never dated before this (= origin entry date).
+  posting_floor_date: string
+  status: AccrualScheduleStatus
+  description: string | null
+  created_at: string
+  updated_at: string
+  // Relations
+  installments?: AccrualScheduleInstallment[]
+}
+
+export interface AccrualScheduleInstallment {
+  id: string
+  user_id: string
+  company_id: string
+  schedule_id: string
+  // First day of the calendar month the installment belongs to.
+  period_month: string
+  amount: number
+  status: AccrualInstallmentStatus
+  journal_entry_id: string | null
+  posted_at: string | null
+  last_error: string | null
+  created_at: string
+  updated_at: string
+}
+
 // Mapping Rule
 export interface MappingRule {
   id: string
@@ -2925,6 +2997,11 @@ export interface InvoiceExtractionResult {
     dueDate: string | null
     paymentReference: string | null
     currency: string
+    // Service/coverage window the invoice charges for — drives the
+    // periodisering prefill. Optional: extractions from before the field
+    // existed lack it.
+    servicePeriodStart?: string | null
+    servicePeriodEnd?: string | null
   }
   lineItems: ExtractedInvoiceLineItem[]
   totals: {