fix(vat): complete account treatment enforcement (#1593)

* fix(vat): complete account treatment enforcement

* docs(api): refresh account endpoint skill

* fix(mcp): preserve ruta 05 compatibility

* test(vat): seed migration constraint fixtures

* docs(vat): clarify treatment precedence

---------

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

lib/reports/__tests__/vat-declaration.test.ts

@@ -143,14 +143,14 @@ describe('rutorFromTotals: explicit account VAT treatments', () => {
     expect(rutor.ruta20).toBe(1000)
   })
 
-  it('keeps a static BAS mapping authoritative over an explicit treatment', () => {
+  it('lets an explicit treatment replace a static BAS mapping', () => {
     const totals = new Map([['3001', { debit: 0, credit: 1000 }]])
     const rutor = rutorFromTotals(totals, {
       mappingByAccount: new Map([['3001', { box: 'ruta42', side: 'credit' }]]),
       explicitAccounts: new Set(['3001']),
     })
-    expect(rutor.ruta05).toBe(1000)
-    expect(rutor.ruta42).toBe(0)
+    expect(rutor.ruta05).toBe(0)
+    expect(rutor.ruta42).toBe(1000)
   })
 })
 

lib/reports/rc-basis-gaps.ts

@@ -150,8 +150,9 @@ export async function findRcBasisGaps(
 
   const basisByEntryAndRate = new Map<string, number>()
   for (const line of siblingLines) {
-    const rate = STATIC_RC_BASIS_RATE.get(line.account_number) ??
-      dynamicVatAccounts.rcBasisRateByAccount.get(line.account_number)
+    const rate = dynamicVatAccounts.explicitAccounts.has(line.account_number)
+      ? dynamicVatAccounts.rcBasisRateByAccount.get(line.account_number)
+      : STATIC_RC_BASIS_RATE.get(line.account_number)
     if (rate) {
       const key = `${line.journal_entry_id}:${rate}`
       const prev = basisByEntryAndRate.get(key) || 0

lib/reports/vat-declaration.ts

@@ -436,6 +436,7 @@ export function rutorFromTotals(
   }
 
   for (const [account, mapping] of Object.entries(ACCOUNT_RUTA)) {
+    if (dynamic?.explicitAccounts.has(account)) continue
     const t = totals.get(account)
     if (!t) continue
     const balance = mapping.side === 'credit'
@@ -445,7 +446,6 @@ export function rutorFromTotals(
   }
 
   for (const [account, mapping] of dynamic?.mappingByAccount ?? []) {
-    if (ACCOUNT_RUTA[account]) continue
     const t = totals.get(account)
     if (!t) continue
     const balance = mapping.side === 'credit' ? t.credit - t.debit : t.debit - t.credit
@@ -561,6 +561,7 @@ export async function calculateVatDeclaration(
   }
   const RATE_BUCKET = { 0.25: 'base25', 0.12: 'base12', 0.06: 'base6' } as const
   for (const [account, rate] of [['3001', 'base25'], ['3002', 'base12'], ['3003', 'base6']] as const) {
+    if (dynamicVatAccounts.explicitAccounts.has(account)) continue
     const t = totals.get(account)
     if (t) revenueByRate[rate] = round(t.credit - t.debit)
   }

lib/reports/vat-filing-gate.ts

@@ -2,8 +2,8 @@ import type {
   VatDeclarationCheck,
   VatCheckAccountTotals,
 } from './vat-declaration-checks'
-import type { VatDeclarationRutor } from '@/types'
 import { roundOre } from '@/lib/money'
+import type { VatDeclarationRutor } from '@/types'
 
 /**
  * The filing gate for the momsdeklaration: ONE derived value that the
@@ -94,12 +94,6 @@ export const RC_BASIS_ACCOUNTS_BY_RATE = {
   r6: ['4517', '4537', '4533', '4417', '4427'],
 } as const
 
-const STATIC_RC_BASIS_ACCOUNTS = new Set<string>([
-  ...RC_BASIS_ACCOUNTS_BY_RATE.r25,
-  ...RC_BASIS_ACCOUNTS_BY_RATE.r12,
-  ...RC_BASIS_ACCOUNTS_BY_RATE.r6,
-])
-
 /** Net debit balance of the RC basis accounts, one figure per momssats. */
 export interface RcBasisTotalsByRate {
   r25: number
@@ -120,6 +114,7 @@ export function rcBasisTotalsByRate(
   const sumGroup = (accounts: readonly string[]): number => {
     let sum = 0
     for (const account of accounts) {
+      if (dynamic?.explicitAccounts.has(account)) continue
       const t = totals.get(account)
       if (t) sum += t.debit - t.credit
     }
@@ -131,7 +126,6 @@ export function rcBasisTotalsByRate(
     r6: sumGroup(RC_BASIS_ACCOUNTS_BY_RATE.r6),
   }
   for (const [account, rate] of dynamic?.rcBasisRateByAccount ?? []) {
-    if (STATIC_RC_BASIS_ACCOUNTS.has(account)) continue
     const total = totals.get(account)
     if (!total) continue
     const key = rate === 0.25 ? 'r25' : rate === 0.12 ? 'r12' : 'r6'

lib/reports/vat-revenue-accounts.ts

@@ -42,7 +42,7 @@ const emptyDynamicVatAccounts = (): DynamicVatAccounts => ({
   rcBasisRateByAccount: new Map(),
 })
 
-/** Explicit treatments extend custom accounts; fixed BAS mappings stay authoritative. */
+/** Explicit account treatments win; accounts without one keep BAS fallback. */
 export async function fetchDynamicVatAccounts(
   supabase: SupabaseClient,
   companyId: string,
@@ -58,7 +58,6 @@ export async function fetchDynamicVatAccounts(
       .select('account_number, account_name, account_class, default_vat_rate, default_vat_treatment')
       .eq('company_id', companyId)
       .in('account_class', [3, 4, 5, 6])
-      .not('is_active', 'is', false)
       .order('account_number', { ascending: true })
       .range(from, to),
   )
@@ -66,27 +65,25 @@ export async function fetchDynamicVatAccounts(
   const result = emptyDynamicVatAccounts()
   for (const row of rows) {
     const account = row.account_number
-    const accountClass = Number(row.account_class ?? account.charAt(0))
     const configuredRate = row.default_vat_rate === null ? null : Number(row.default_vat_rate)
 
     if (isAccountVatTreatment(row.default_vat_treatment)) {
-      if (ACCOUNT_TO_BOX[account]) {
-        if (
-          RUTA_05_STATIC_RATE_ACCOUNTS.has(account) &&
-          configuredRate !== null && TAXABLE_RATES.includes(configuredRate)
-        ) {
-          result.staticRateByAccount.set(account, configuredRate)
-        }
-        continue
-      }
-      const mapping = resolveVatTreatmentRuta(row.default_vat_treatment, accountClass)
-      if (!mapping) continue
       result.explicitAccounts.add(account)
+      const mapping = resolveVatTreatmentRuta(
+        row.default_vat_treatment,
+        row.account_class,
+        row.account_number,
+      )
+      if (!mapping) continue
       result.mappingByAccount.set(account, mapping)
+      // Always include an explicit account in the ledger filter. The Set in
+      // fetchVatAccountTotals deduplicates static BAS accounts, while this also
+      // covers accounts that exist only in the separate moms-box mirror.
       result.accounts.push(account)
-      const rate = configuredRate ?? defaultRateForVatTreatment(row.default_vat_treatment, accountClass)
+      const rate = configuredRate ?? defaultRateForVatTreatment(row.default_vat_treatment, row.account_class)
       if (mapping.box === 'ruta05' && rate !== null && TAXABLE_RATES.includes(rate)) {
-        result.rateByAccount.set(account, rate)
+        const target = ACCOUNT_TO_BOX[account] ? result.staticRateByAccount : result.rateByAccount
+        target.set(account, rate)
       }
       if (
         ['ruta20', 'ruta21', 'ruta22', 'ruta23', 'ruta24'].includes(mapping.box) &&
@@ -97,7 +94,7 @@ export async function fetchDynamicVatAccounts(
       continue
     }
 
-    if (accountClass !== 3) continue
+    if (row.account_class !== 3) continue
     const rate = configuredRate ?? inferDomesticSalesRate(account, row.account_name)
     if (rate === null || !TAXABLE_RATES.includes(rate)) continue
     if (ACCOUNT_TO_BOX[account]) {