feat: reverse charge VAT (ruta 20-32) + mobile UX improvements (#50)

* fix: include reversed entries in all reports (general ledger, trial balance, VAT, SIE, NE, INK2)

Reversed entries (storno) must appear alongside their original posted entries
in reports for a complete audit trail. Previously, filtering by status='posted'
excluded them, causing discrepancies when corrections had been made.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: semi-manual invoice payment booking with editable journal lines

When marking an invoice as paid, users now see a dialog where they can:
- Choose which bank/cash account the payment goes to (1910, 1920, 1930, etc.)
- Review and edit the proposed journal entry lines before committing
- The happy path remains fast — lines are pre-filled correctly

Implementation:
- Pure proposePaymentLines() function for line computation (accrual + cash)
- PaymentBookingDialog with AccountCombobox, balance validation, date picker
- API accepts optional custom lines, falls back to auto-generation without them
- 18 tests (8 unit + 10 API) all passing

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: address Greptile review — validation fallback, balance check, error handling

- P1: Return 400 on invalid body instead of silently falling back to
  auto-generated lines (split JSON parse from schema validation)
- P1: Add server-side balance check for custom lines before committing
  (debit must equal credit, totalDebit > 0)
- P2: Wrap PaymentBookingDialog init() in try/catch with toast on
  failure and auto-close instead of silent empty state
- Add 2 new tests: unbalanced lines → 400, invalid schema → 400

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: OAuth callback redirect for local dev and timeout resilience

- Pass redirectUri dynamically from NEXT_PUBLIC_APP_URL so OAuth
  callbacks work on localhost (not just production)
- Encode consentId/provider in OAuth state (base64url JSON) so the
  callback doesn't depend on session storage
- Add skipAuth flag to extension API routes for OAuth callbacks
  (external provider redirects have no user session cookie)
- Wrap AbortError in descriptive timeout messages in arcim-client
- Make preview endpoint resilient to partial failures (company info
  and SIE fetch are individually non-blocking)
- Simplify login page (remove unused magic link auth mode)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: create journal entry before marking invoice as paid

Move journal entry creation before the invoice status update so that
if accounting fails, the invoice is not permanently marked paid without
a corresponding entry. Previously the error was silently swallowed.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: update mark-paid tests for journal-first ordering

Reorder mock queue to match new flow (settings before update), update
failure test to expect 500 instead of silent success, add try-catch
with proper error response in route handler.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: add reverse charge VAT (ruta 20-32) and improve mobile UX across dashboard

Add full reverse charge (omvänd skattskyldighet) support to the VAT declaration:
- Map accounts 2614/2624/2634 to ruta 30/31/32 for self-assessed output VAT
- Calculate purchase bases (ruta 20-24) from supplier invoices by supplier type
- Include ruta 30-32 in ruta 49 formula and totalOutputVat summary
- Display reverse charge section in reports UI and composition chart
- Add comprehensive test coverage for all reverse charge scenarios

Improve mobile UX across the app:
- Convert nav drawer to bottom sheet with drag handle and safe area padding
- Add mobile card layout for PaymentBookingDialog journal lines
- Replace settings tab pills with dropdown selector on mobile
- Make wizard step indicators responsive (collapsed on mobile)
- Ensure all dialog footers stack buttons full-width on mobile
- Add 44px minimum touch targets throughout
- Make onboarding buttons full-width on mobile

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: address Greptile review — indentation, query efficiency, tab dedup

- Fix misleading try-block indentation in mark-paid route
- Filter reversed entries at DB level (.eq('status', 'posted')) instead
  of fetching then discarding in memory
- Extract shared settingsTabs array so mobile Select and desktop
  TabsList stay in sync automatically

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

types/index.ts

@@ -1550,6 +1550,18 @@ export interface VatDeclarationRutor {
   ruta11: number  // Utgående moms 12%
   ruta12: number  // Utgående moms 6%
 
+  // Inköp vid omvänd skattskyldighet (reverse charge purchase bases)
+  ruta20: number  // Inköp av varor från annat EU-land (unused, goods via Tullverket)
+  ruta21: number  // Inköp av tjänster från annat EU-land
+  ruta22: number  // Inköp av tjänster från land utanför EU
+  ruta23: number  // Inköp av varor i Sverige (unused, construction reverse charge goods)
+  ruta24: number  // Övriga inköp av tjänster i Sverige (domestic reverse charge)
+
+  // Utgående moms omvänd skattskyldighet (self-assessed output VAT on reverse charge)
+  ruta30: number  // Utgående moms 25% omvänd skattskyldighet
+  ruta31: number  // Utgående moms 12% omvänd skattskyldighet
+  ruta32: number  // Utgående moms 6% omvänd skattskyldighet
+
   // EU och export
   ruta39: number  // Försäljning av tjänster till annat EU-land (reverse charge)
   ruta40: number  // Export utanför EU
@@ -1596,6 +1608,16 @@ export interface VatDeclaration {
     receipts: {
       ruta48: number  // Ingående moms from receipts
     }
+    reverseCharge: {
+      ruta20: number
+      ruta21: number
+      ruta22: number
+      ruta23: number
+      ruta24: number
+      ruta30: number
+      ruta31: number
+      ruta32: number
+    }
   }
 }
 
@@ -1614,6 +1636,14 @@ export const VAT_RUTA_LABELS: Record<keyof VatDeclarationRutor, string> = {
   ruta10: 'Utgående moms 25%',
   ruta11: 'Utgående moms 12%',
   ruta12: 'Utgående moms 6%',
+  ruta20: 'Inköp av varor från annat EU-land',
+  ruta21: 'Inköp av tjänster från annat EU-land',
+  ruta22: 'Inköp av tjänster från land utanför EU',
+  ruta23: 'Inköp av varor i Sverige',
+  ruta24: 'Övriga inköp av tjänster i Sverige',
+  ruta30: 'Utgående moms 25% (omvänd skattskyldighet)',
+  ruta31: 'Utgående moms 12% (omvänd skattskyldighet)',
+  ruta32: 'Utgående moms 6% (omvänd skattskyldighet)',
   ruta39: 'Försäljning av tjänster till EU-land',
   ruta40: 'Export utanför EU',
   ruta48: 'Ingående moms att dra av',