feat: per-line VAT, invoice document types, ledger-based VAT declaration, bank reconciliation, and pagination

Per-line VAT rates:
- Add generatePerRateLines() to group invoice items by vat_rate with separate
  revenue + VAT lines per rate group (invoice-entries.ts)
- Add getAvailableVatRates() and getVatTreatmentForRate() (vat-rules.ts)
- PDF template shows per-line VAT column and per-rate totals for mixed-rate invoices
- Invoice create/review UI supports per-line rate selection
- Types: add vat_rate/vat_amount to InvoiceItem, vat_rate to CreateInvoiceItemInput

Invoice document types (proforma, delivery note):
- Add InvoiceDocumentType, document_type and converted_from_id to Invoice type
- PDF hides prices for delivery notes, adds proforma notice
- Email templates support all document types
- mark-paid skips journal entries for non-invoice document types
- Migration 031: invoice_document_type

Accounting method support:
- Add AccountingMethod type (accrual/cash)
- Migration 032: add_accounting_method column to company_settings

VAT declaration rewrite:
- Rewrite to read directly from general ledger (26xx/3xxx account lines)
  instead of aggregating invoices/transactions/receipts
- ACCOUNT_RUTA mapping drives momsdeklaration boxes from GL balances

Bank reconciliation:
- Transaction ingest now pre-fetches unlinked GL lines and attempts
  auto-reconciliation during import
- Add transaction.reconciled event type
- Add ReconciliationMethod type and reconciliation_method on Transaction
- Migration 030: bank_reconciliation
- New reconciliation engine, API routes, and BankReconciliationView component

Pagination (fetchAllRows):
- New lib/supabase/fetch-all.ts overcomes PostgREST 1000-row limit
- Adopted in all report generators, SIE/SRU export, account list APIs

Fiscal period validation:
- New validate-period-duration.ts enforces max 18 months per BFL 3 kap.
- Applied in period-service.ts and fiscal-periods API

Account mapper simplification:
- Remove Levenshtein/fuzzy matching, use exact account number match only

Swedbank parser improvements:
- Support abbreviated headers (Clnr, Bokfdag, Radnr)
- Use Referens column as counterparty

Chart of accounts management:
- Add DELETE endpoint with system account and usage protection
- PUT uses partial updates
- New AccountCombobox, AddAccountDialog, EditAccountDialog, ChartOfAccountsManager

Tax deadline corrections:
- Rewrite inkomstdeklaration_ab using Skatteverket lookup table
- Rewrite arsredovisning deadline to 7 months after FY end per ÅRL 8:3

Onboarding first fiscal year:
- Add first fiscal year toggle with date pickers and 18-month validation

UI terminology:
- Change "okategoriserad/kategorisera" to "obokförd/bokföra" throughout

Report column fix:
- Fix start_date/end_date to period_start/period_end in report queries

Supplier invoice input:
- CreateSupplierInvoiceItemInput uses amount field (legacy quantity/unit_price kept)

Misc:
- SIE import uses upsert for idempotent account creation
- account-descriptions.ts falls back to BAS reference data
- Add invoice_default_notes to CompanySettings
- Update CLAUDE.md to reflect current project state

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

supabase/migrations/20240101000030_bank_reconciliation.sql

@@ -0,0 +1,70 @@
+-- Bank reconciliation support
+-- Adds reconciliation_method to transactions, indexes for fast lookups,
+-- and an RPC function to find unlinked 1930 journal entry lines.
+
+-- Add reconciliation_method column to transactions
+ALTER TABLE public.transactions
+  ADD COLUMN IF NOT EXISTS reconciliation_method TEXT
+  CHECK (reconciliation_method IN (
+    'auto_exact', 'auto_date_range', 'auto_reference', 'auto_fuzzy', 'manual'
+  ));
+
+-- Index for fast lookup of unreconciled transactions (no journal entry linked)
+CREATE INDEX IF NOT EXISTS idx_transactions_unmatched
+  ON public.transactions (user_id, date)
+  WHERE journal_entry_id IS NULL;
+
+-- Index for fast lookup of bank account GL lines
+CREATE INDEX IF NOT EXISTS idx_journal_entry_lines_1930
+  ON public.journal_entry_lines (account_number, journal_entry_id)
+  WHERE account_number = '1930';
+
+-- RPC function: returns posted journal entry lines on account 1930
+-- that have no linked transaction (i.e., unreconciled GL lines).
+CREATE OR REPLACE FUNCTION public.get_unlinked_1930_lines(
+  p_user_id UUID,
+  p_date_from DATE DEFAULT NULL,
+  p_date_to DATE DEFAULT NULL
+)
+RETURNS TABLE (
+  line_id UUID,
+  journal_entry_id UUID,
+  debit_amount NUMERIC,
+  credit_amount NUMERIC,
+  line_description TEXT,
+  entry_date DATE,
+  voucher_number INT,
+  voucher_series TEXT,
+  entry_description TEXT,
+  source_type TEXT
+)
+LANGUAGE sql
+STABLE
+SECURITY DEFINER
+AS $$
+  SELECT
+    jel.id AS line_id,
+    je.id AS journal_entry_id,
+    jel.debit_amount,
+    jel.credit_amount,
+    jel.line_description,
+    je.entry_date,
+    je.voucher_number,
+    je.voucher_series,
+    je.description AS entry_description,
+    je.source_type
+  FROM public.journal_entry_lines jel
+  JOIN public.journal_entries je ON je.id = jel.journal_entry_id
+  WHERE jel.account_number = '1930'
+    AND je.user_id = p_user_id
+    AND je.status = 'posted'
+    AND (p_date_from IS NULL OR je.entry_date >= p_date_from)
+    AND (p_date_to IS NULL OR je.entry_date <= p_date_to)
+    AND NOT EXISTS (
+      SELECT 1
+      FROM public.transactions t
+      WHERE t.journal_entry_id = je.id
+        AND t.user_id = p_user_id
+    )
+  ORDER BY je.entry_date, je.voucher_number;
+$$;

supabase/migrations/20240101000031_invoice_document_type.sql

@@ -0,0 +1,19 @@
+-- Add document_type and converted_from_id to invoices
+-- Supports proforma invoices and delivery notes alongside standard invoices
+
+ALTER TABLE public.invoices
+  ADD COLUMN IF NOT EXISTS document_type text NOT NULL DEFAULT 'invoice'
+    CHECK (document_type IN ('invoice', 'proforma', 'delivery_note'));
+
+ALTER TABLE public.invoices
+  ADD COLUMN IF NOT EXISTS converted_from_id uuid
+    REFERENCES public.invoices(id) ON DELETE SET NULL;
+
+-- Index for filtering by document type
+CREATE INDEX IF NOT EXISTS idx_invoices_document_type
+  ON public.invoices (document_type);
+
+-- Index for looking up conversions
+CREATE INDEX IF NOT EXISTS idx_invoices_converted_from_id
+  ON public.invoices (converted_from_id)
+  WHERE converted_from_id IS NOT NULL;

supabase/migrations/20240101000032_add_accounting_method.sql

@@ -0,0 +1,5 @@
+-- Add accounting_method column to company_settings
+-- Supports kontantmetoden (cash) vs faktureringsmetoden (accrual)
+ALTER TABLE public.company_settings
+  ADD COLUMN IF NOT EXISTS accounting_method text NOT NULL DEFAULT 'accrual'
+  CHECK (accounting_method IN ('accrual', 'cash'));