Fix/build (#1041)

* fix(bookkeeping): harden correction account changes

* feat(tax): enhance tax deadline generation with new settings and filing methods

- Added new company settings: tax_turnover_over_40m, vat_has_eu_trade, vat_filing_method, periodisk_sammanstallning_enabled, and periodisk_sammanstallning_filing_method.
- Updated deadline generation logic to accommodate new settings affecting VAT and employer declaration deadlines.
- Implemented tests for new functionality, ensuring that completed obligations are preserved and not replaced by new pending rows.
- Introduced a cron job to backfill missing tax deadlines for companies with settings but no upcoming deadlines.
- Updated API routes for generating tax deadlines and handling cron jobs.
- Modified database schema to include new columns for tax filing profiles and constraints for filing methods.

* fix(invoices): record credit note reconciliation guard

* fix(tax): correct automatic deadline settings

* fix(tax): key AGI deadline to VAT taxable base and add storforetag payment deadline

The 26th filing day for the skattedeklaration (AGI and VAT together) hinges
on one statutory measure, a VAT taxable base above SEK 40 million (SFL 26
kap.), not a separate employer turnover. Drop employer_turnover_over_40m and
derive the AGI schedule from vat_registered plus vat_taxable_base_over_40m,
so a non-VAT-reporting employer is never shown the 26th when its binding
date is the 12th.

Also:
- add a skatteinbetalning deadline row (12th, 17 January) for storforetag,
  whose deducted tax and employer contributions are due before the 26th
  filing date
- normalize legally incoherent over-40m flag combinations to the earlier
  small-company schedule in a follow-up migration
- replace hardcoded 27 December dates with the banking-day adjustment
- extend the 40m help text to cover the SKV-decided early filing election
  and the payment-still-on-the-12th rule
- document the regeneration race repaired by the daily backfill cron

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

* feat(migrations): add AGI and VAT filing logic with employer column removal

* feat(settings): implement VAT registration logic and update related flags; enhance deadline handling

---------

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

lib/api/__tests__/schemas.test.ts

@@ -1358,6 +1358,20 @@ describe('UpdateSettingsSchema', () => {
     expect(result.success).toBe(true)
   })
 
+  it('validates tax deadline filing-profile fields', () => {
+    expect(UpdateSettingsSchema.safeParse({
+      vat_taxable_base_over_40m: true,
+      vat_has_eu_trade: true,
+      vat_filing_method: 'electronic',
+      periodisk_sammanstallning_enabled: true,
+      periodisk_sammanstallning_filing_method: 'paper',
+    }).success).toBe(true)
+    expect(UpdateSettingsSchema.safeParse({ vat_filing_method: 'fax' }).success).toBe(false)
+    expect(UpdateSettingsSchema.safeParse({
+      periodisk_sammanstallning_filing_method: 'fax',
+    }).success).toBe(false)
+  })
+
   it('rejects invalid email', () => {
     const result = UpdateSettingsSchema.safeParse({ email: 'not-email' })
     expect(result.success).toBe(false)

lib/api/schemas.ts

@@ -244,6 +244,7 @@ export const TaxDeadlineTypeSchema = z.enum([
   'moms_yearly',
   'f_skatt',
   'arbetsgivardeklaration',
+  'skatteinbetalning',
   'inkomstdeklaration_ef',
   'inkomstdeklaration_ab',
   'arsredovisning',
@@ -256,6 +257,7 @@ export const DeadlineSourceSchema = z.enum(['system', 'user'])
 export const MomsPeriodSchema = z.enum(['monthly', 'quarterly', 'yearly'])
 
 export const PsPeriodTypeSchema = z.enum(['monthly', 'quarterly'])
+export const TaxFilingMethodSchema = z.enum(['electronic', 'paper'])
 
 export const DocumentUploadSourceSchema = z.enum([
   'camera', 'file_upload', 'email', 'e_invoice', 'scan', 'api', 'system',
@@ -1442,7 +1444,12 @@ export const UpdateSettingsSchema = z.object({
     .nullable()
     .optional(),
   moms_period: MomsPeriodSchema.nullable().optional(),
+  vat_taxable_base_over_40m: z.boolean().optional(),
+  vat_has_eu_trade: z.boolean().optional(),
+  vat_filing_method: TaxFilingMethodSchema.optional(),
+  periodisk_sammanstallning_enabled: z.boolean().optional(),
   periodisk_sammanstallning_period: PsPeriodTypeSchema.optional(),
+  periodisk_sammanstallning_filing_method: TaxFilingMethodSchema.optional(),
   tax_contact_name: z.string().max(200).nullable().optional(),
   tax_contact_phone: z.string().max(40).nullable().optional(),
   tax_contact_email: z.string().email().nullable().optional().or(z.literal('')),