fix(arsredovisning): make the aktiekapital note completable via compa… (#1118)

* fix(arsredovisning): make the aktiekapital note completable via company settings

The annual report warned every AB that the aktiekapital note was missing
and pointed at Installningar -> Foretag, but the referenced columns
(aktiekapital, antal_aktier, kvotvarde) never existed and no settings UI
was ever built, so the warning was a dead end and no AB could produce a
complete note before Bolagsverket filing.

- migration 20260723103000: company_settings.aktiekapital (numeric) and
  antal_aktier (integer) with positive CHECKs; kvotvarde is intentionally
  not stored since ABL 1 kap 6 defines it as aktiekapital / antal aktier
- build-data.ts (K2 and K3 note paths): select only the two stored
  columns and derive kvotvarde with roundOre
- UpdateSettingsSchema: aktiekapital (positive), antal_aktier (positive
  integer), both nullable to allow clearing
- new ShareCapitalForm section on Installningar -> Foretag, rendered for
  aktiebolag only, with live derived kvotvarde display; wired through the
  existing CompanySettingsContent save path (empty string clears to null)
- sv/en strings; settings route tests (round-trip, clear, 400 on invalid);
  builder tests for derived kvotvarde and the empty-settings warning

Staging (metjnjrhvujscngnpzdv) already has the columns applied and the
note verified end-to-end against a rehearsal company.

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

* fix(arsredovisning): address PR review findings on the share-capital note

- enforce aktiekapital/antal_aktier as an all-or-nothing pair (DB CHECK,
  K2/K3 note guard now requires both, partial pair warns instead)
- numeric(15,2) column, .int() Zod constraint, maxFractionDigits 0 render
- guard numberOrNull against NaN; align kvotvarde preview with schema
- strengthen clearing test, add fractional and partial-pair tests

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

---------

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

components/settings/sections/CompanySettingsContent.tsx

@@ -10,6 +10,7 @@ import { LogoUpload } from '@/components/settings/LogoUpload'
 import { SettingsFormWrapper } from '@/components/settings/SettingsFormWrapper'
 import { SettingsLoadError } from '@/components/settings/SettingsLoadError'
 import { SettingsLoadingSkeleton } from '@/components/settings/SettingsLoadingSkeleton'
+import { ShareCapitalForm } from '@/components/settings/ShareCapitalForm'
 import { useSettings } from '@/components/settings/useSettings'
 import type { CompanySettings } from '@/types'
 
@@ -21,6 +22,14 @@ export function CompanySettingsContent() {
   if (!settings) return <SettingsLoadError onRetry={refetch} />
 
   function handleSave(formData: FormData) {
+    // Empty string clears the value (schema accepts null, not '').
+    const numberOrNull = (name: string) => {
+      const raw = String(formData.get(name) ?? '').trim()
+      if (raw === '') return null
+      const parsed = Number(raw)
+      // NaN would serialize to null in JSON and silently clear the value.
+      return Number.isFinite(parsed) ? parsed : null
+    }
     const updates: Record<string, unknown> = {
       ...(formData.has('company_name') && { company_name: formData.get('company_name') as string }),
       ...(formData.has('org_number') && { org_number: formData.get('org_number') as string }),
@@ -30,6 +39,8 @@ export function CompanySettingsContent() {
       phone: (formData.get('phone') as string) || '',
       email: (formData.get('email') as string) || '',
       website: (formData.get('website') as string) || '',
+      ...(formData.has('aktiekapital') && { aktiekapital: numberOrNull('aktiekapital') }),
+      ...(formData.has('antal_aktier') && { antal_aktier: numberOrNull('antal_aktier') }),
     }
     return {
       updates,
@@ -48,6 +59,7 @@ export function CompanySettingsContent() {
     <div className="space-y-8">
       <SettingsFormWrapper onSave={handleSave} className="space-y-8">
         <CompanyInfoForm settings={settings} />
+        {settings.entity_type === 'aktiebolag' && <ShareCapitalForm settings={settings} />}
       </SettingsFormWrapper>
 
       <div className="border-t border-border pt-8">