fix(vat): keep the RC-basis worklist visible until every voucher is fixed (#1164)

Correcting a single voucher cleared the momsdeklaration's RC_BASIS_MISSING
error and the whole per-voucher worklist with it: the check tested mere
presence of ruta 20-24 basis, the stepper re-derived its landing step and
yanked the user to Granska mid-work, and the remounted checks card never
refetched gaps once the aggregate check stopped firing. The declaration
then claimed "klart" while the remaining vouchers still under-reported
rutor 20-24 (FK004).

- Make RC_BASIS_MISSING/RC_OUTPUT_MISSING proportional: compare reported
  basis against the basis the per-rate output boxes imply (moms/sats),
  with a 0.5% + 1 kr tolerance for per-voucher ore rounding.
- Fetch the rc-basis-gaps worklist once per period, ungated from the
  aggregate check, so remaining rows survive remounts.
- Latch the automatic stepper landing once per period so a refetch after
  a korrigering cannot navigate the user off Kontrollera.
- Resolve rc-basis-gaps against the rakenskapsar (fiscal_period_id) for
  helarsmoms, matching the declaration totals; a calendar span hid gap
  vouchers in the tail of an extended first year.

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

components/reports/VatChecksCard.tsx

@@ -107,10 +107,9 @@ export function VatChecksCard({
   // Gap fetch tagged with the key it was requested under: loading is derived
   // by comparing tags, so the effect never sets state synchronously. Fixed
   // rows are removed via removedIds (the fetch itself is not re-run after a
-  // korrigering: the period key is unchanged). The key is period-only, NOT
-  // gated on RC_BASIS_MISSING: the aggregate check clears as soon as ONE
-  // voucher is corrected, and the remaining unfixed rows must survive the
-  // declaration refetch that follows each korrigering.
+  // korrigering: the period key is unchanged). The key is period-only so the
+  // list survives the declaration refetch that follows each korrigering, and
+  // survives a remount even when the aggregate check no longer fires.
   const gapsKey = `${periodType}:${year}:${period}:${fiscalPeriodId ?? ''}`
   const [gapsResult, setGapsResult] = useState<{
     key: string
@@ -145,25 +144,26 @@ export function VatChecksCard({
   const gapsFetched = gapsResult !== null && gapsResult.key === gapsKey
 
   useEffect(() => {
-    // Fetch once per period, and only while the aggregate check flags a gap:
-    // the fetched list then outlives the check, which clears after the first
-    // correction even though other vouchers may remain broken.
-    if (!hasRcBasisGaps || gapsFetched) return
+    // Fetch once per period, NOT gated on the aggregate check: the check
+    // compares period totals and can clear (or never fire) while individual
+    // vouchers still miss their basis pair. Gating the fetch on it meant a
+    // remount after the first korrigering showed "inga fel" with the
+    // remaining broken vouchers silently hidden.
+    if (gapsFetched) return
     let cancelled = false
     const params = new URLSearchParams({
       periodType,
       year: String(year),
       period: String(period),
     })
-    // Forward-compatible: the route reads calendar params today, but yearly
-    // (helårsmoms) declarations resolve against the räkenskapsår.
+    // Yearly (helårsmoms) resolves against the räkenskapsår server-side.
     if (fiscalPeriodId) params.set('fiscal_period_id', fiscalPeriodId)
     fetch(`/api/reports/vat-declaration/rc-basis-gaps?${params.toString()}`)
       .then(async (r) => {
         const j = await r.json().catch(() => null)
         if (cancelled) return
-        // A failed fetch must not masquerade as "no gaps found": the check
-        // above says there ARE gaps, so an empty list here would mislead.
+        // A failed fetch must not masquerade as "no gaps found": an empty
+        // list would mislead whenever gaps actually exist.
         if (!r.ok || j?.error) setGapsResult({ key: gapsKey, gaps: [], failed: true })
         else setGapsResult({ key: gapsKey, gaps: j?.data?.gaps || [] })
       })
@@ -173,7 +173,7 @@ export function VatChecksCard({
     return () => {
       cancelled = true
     }
-  }, [hasRcBasisGaps, gapsFetched, gapsKey, periodType, year, period, fiscalPeriodId])
+  }, [gapsFetched, gapsKey, periodType, year, period, fiscalPeriodId])
 
   const gaps = gapsFetched
     ? gapsResult.gaps.filter((g) => !removedIds.has(g.entryId))

components/reports/views/index.tsx

@@ -1627,6 +1627,16 @@ export function VatDeclarationView() {
   const checksBlocked = checks.some((c) => c.status === 'ERROR')
   const errorCount = checks.filter((c) => c.status === 'ERROR').length
   const warningCount = checks.filter((c) => c.status === 'WARNING').length
+  // Latch the automatic landing step once per period, as a render-phase
+  // adjustment when the period's declaration first settles. Deriving it live
+  // from checksBlocked navigated the user away mid-work: the refetch after a
+  // korrigering can clear the aggregate error while the Kontrollera worklist
+  // still holds broken vouchers, and the view would jump to Granska under
+  // their feet. The period-change effect below resets chosenStep to null,
+  // which re-arms this latch for the next period.
+  if (chosenStep === null && upToDate && data && !error) {
+    setChosenStep(checksBlocked ? 1 : 2)
+  }
   const activeStep = chosenStep ?? (checksBlocked ? 1 : 2)
 
   // Settings not settled yet — the picker defaults and the gate both depend