fix(salary): recompute entitled_days on existing ledger rows and record pre-cutover taken days (#1403)

The vacation ledger sync carried entitled_days verbatim on existing open
rows while re-deriving accrued and taken, so a stale entitled value (for
example the flat 25 stored before Semesterlagen 7 § pro-rating existed)
survived every sync. The recompute loop now re-derives entitled the same
way the lazy-seed path does, with the opening-balance cutover still
outranking recomputation for the year containing cutover_date.

Opening balances could also not record paid vacation days already taken
in the cutover year under the previous payroll system. New additive
column employee_opening_balances.vacation_days_taken_this_year (NUMERIC
NOT NULL DEFAULT 0, CHECK 0..40) threaded through the shared service,
the Zod schema, the MCP staging tool (schema + mergeable fields), the
staged-operation executor, the v1 REST routes, and the employee editor
form. Ledger semantics for the cutover year, on both seed and recompute
paths: entitled = remaining + taken_this_year, taken = booked-run taken
+ taken_this_year, so remaining keeps meaning remaining and the seeded
value survives every subsequent sync.

Fixes #1347

Co-authored-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

app/api/v1/companies/[companyId]/employees/[id]/opening-balances/__tests__/route.test.ts

@@ -88,6 +88,7 @@ const SAMPLE_ROW = {
   ytd_tax: 48000,
   ytd_net: 162000,
   vacation_paid_days_remaining: 12.5,
+  vacation_days_taken_this_year: 2,
   vacation_saved_days_by_year: { [`${CURRENT_YEAR - 1}`]: 5 },
   opening_semester_liability: 42000,
   opening_semester_liability_avgifter: 13196.4,
@@ -102,6 +103,7 @@ const VALID_BODY = {
   ytd_tax: 48000,
   ytd_net: 162000,
   vacation_paid_days_remaining: 12.5,
+  vacation_days_taken_this_year: 2,
   vacation_saved_days_by_year: { [`${CURRENT_YEAR - 1}`]: 5 },
   opening_semester_liability: 42000,
   opening_semester_liability_avgifter: 13196.4,
@@ -244,9 +246,42 @@ describe('PUT /employees/:id/opening-balances', () => {
     expect(res.status).toBe(200)
     const body = await res.json()
     expect(body.data.employee_opening_balances_id).toBe(ROW_ID)
+    expect(body.data.vacation_days_taken_this_year).toBe(2)
     expect(body.data.locked).toBe(false)
   })
 
+  it('rejects vacation_days_taken_this_year below 0', async () => {
+    mockServiceClient.mockReturnValue(
+      makeFlexibleSupabase({
+        company_members: { data: { company_id: COMPANY_ID, role: 'owner' }, error: null },
+      }),
+    )
+    const res = await putBalances(
+      makeRequest(
+        `https://x.test/api/v1/companies/${COMPANY_ID}/employees/${EMPLOYEE_ID}/opening-balances`,
+        { method: 'PUT', body: JSON.stringify({ ...VALID_BODY, vacation_days_taken_this_year: -1 }) },
+      ),
+      detailParams(COMPANY_ID, EMPLOYEE_ID),
+    )
+    expect(res.status).toBe(400)
+  })
+
+  it('rejects vacation_days_taken_this_year above 40', async () => {
+    mockServiceClient.mockReturnValue(
+      makeFlexibleSupabase({
+        company_members: { data: { company_id: COMPANY_ID, role: 'owner' }, error: null },
+      }),
+    )
+    const res = await putBalances(
+      makeRequest(
+        `https://x.test/api/v1/companies/${COMPANY_ID}/employees/${EMPLOYEE_ID}/opening-balances`,
+        { method: 'PUT', body: JSON.stringify({ ...VALID_BODY, vacation_days_taken_this_year: 41 }) },
+      ),
+      detailParams(COMPANY_ID, EMPLOYEE_ID),
+    )
+    expect(res.status).toBe(400)
+  })
+
   it('returns 409 OPENING_BALANCES_LOCKED when a booked run exists', async () => {
     mockServiceClient.mockReturnValue(
       makeFlexibleSupabase({

app/api/v1/companies/[companyId]/employees/[id]/opening-balances/route.ts

@@ -33,6 +33,7 @@ const OpeningBalancesResponse = z.object({
   ytd_tax: z.number(),
   ytd_net: z.number(),
   vacation_paid_days_remaining: z.number(),
+  vacation_days_taken_this_year: z.number(),
   vacation_saved_days_by_year: z.record(z.string(), z.number()),
   opening_semester_liability: z.number(),
   opening_semester_liability_avgifter: z.number(),
@@ -114,7 +115,7 @@ registerEndpoint({
   path: '/api/v1/companies/:companyId/employees/:id/opening-balances',
   summary: 'Set an employee\'s payroll cutover opening balances.',
   description:
-    'Full-replace upsert of the cutover state: YTD gross/tax/net for the cutover year, paid vacation days remaining, sparade dagar keyed by origin year (5-year rule), opening semesterlöneskuld SEK (+avgifter), and karens periods not covered by imported absence rows. cutover_date must be the first of a month in the current or previous year, on/after employment_start.',
+    'Full-replace upsert of the cutover state: YTD gross/tax/net for the cutover year, paid vacation days remaining, paid days already taken this vacation year, sparade dagar keyed by origin year (5-year rule), opening semesterlöneskuld SEK (+avgifter), and karens periods not covered by imported absence rows. cutover_date must be the first of a month in the current or previous year, on/after employment_start.',
   useWhen:
     'Onboarding one employee during a mid-year migration from Fortnox/Visma/etc. For whole-company onboarding, prefer the bulk PUT /employees/opening-balances.',
   doNotUseFor: