feat: AR/AP navigation separation and bookkeeping improvements (#109)

* feat: separate AR/AP/accounting into distinct nav groups (#92)

Split the flat "Finans" sidebar group into three visually distinct
sections — Försäljning (AR), Inköp (AP), and Redovisning — so users
coming from Fortnox immediately find customer invoicing and supplier
invoices as top-level concepts.

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

* feat: journal entry detail view, correction chain, and account name display

- Add journal entry detail page at /bookkeeping/[id] with full entry view
- Add correction chain API and component showing storno relationships
- Add JournalEntryStatusBadge component for entry status display
- Show debit/credit account names in template picker and review dialogs
- Expand client-side BAS account name mapping with additional accounts
- Show account codes on transaction inbox suggestion buttons

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

* fix: address review feedback — N+1 query, duplicate name, nav dedup

- Batch reverse-lookup into single query per BFS iteration (was N+1)
- Differentiate account 2393 from 2893 in display names
- Extract shared loop for desktop/mobile nav group rendering

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

---------

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

lib/bookkeeping/client-account-names.ts

@@ -6,19 +6,26 @@
 
 const ACCOUNT_NAMES: Record<string, string> = {
   // Assets (1xxx)
+  '1250': 'Inventarier',
   '1510': 'Kundfordringar',
+  '1630': 'Skattekonto',
+  '1680': 'Fordringar hos ägare',
   '1930': 'Företagskonto',
 
   // Equity & Liabilities (2xxx)
   '2013': 'Övriga egna uttag',
   '2018': 'Egna insättningar',
+  '2350': 'Långfristiga skulder',
+  '2393': 'Kortfristig skuld närstående',
   '2440': 'Leverantörsskulder',
+  '2510': 'Personalskatt',
   '2611': 'Utg. moms 25%',
   '2621': 'Utg. moms 12%',
   '2631': 'Utg. moms 6%',
   '2614': 'Utg. moms omvänd',
   '2641': 'Ing. moms',
   '2645': 'Beräknad ing. moms',
+  '2731': 'Arbetsgivaravgifter',
   '2893': 'Skuld till ägare',
 
   // Revenue (3xxx)
@@ -29,31 +36,51 @@ const ACCOUNT_NAMES: Record<string, string> = {
   '3305': 'Exportförsäljning',
   '3308': 'EU-tjänster',
   '3900': 'Övriga rörelseintäkter',
+  '3960': 'Valutakursvinster',
 
   // Cost of goods (4xxx)
   '4010': 'Varuinköp',
 
   // External expenses (5xxx)
   '5010': 'Lokalhyra',
+  '5020': 'El & uppvärmning',
   '5410': 'Förbrukningsinventarier',
   '5420': 'Programvaror',
+  '5421': 'Molntjänster',
   '5460': 'Förbrukningsvaror',
   '5611': 'Drivmedel bil',
+  '5613': 'Reparation fordon',
+  '5614': 'Parkering',
+  '5615': 'Leasing fordon',
   '5800': 'Resekostnader',
+  '5810': 'Biljetter & transport',
+  '5820': 'Hotell',
   '5910': 'Annonsering',
+  '5920': 'Design & grafik',
+  '5990': 'Konferens',
 
   // Other external expenses (6xxx)
   '6071': 'Representation',
   '6110': 'Kontorsförbrukning',
   '6200': 'Telefon & internet',
+  '6211': 'Mobiltelefon',
+  '6230': 'Internet',
+  '6250': 'Porto',
+  '6310': 'Företagsförsäkring',
   '6530': 'Redovisningstjänster',
+  '6550': 'Konsulttjänster',
   '6570': 'Bankavgifter',
+  '6980': 'Medlemsavgifter',
   '6991': 'Övriga kostnader',
 
-  // Personnel (7xxx)
+  // Personnel & financial (7xxx / 8xxx)
+  '7210': 'Löner',
+  '7410': 'Pensionsförsäkring',
   '7610': 'Utbildning',
+  '7622': 'Intern representation',
   '7960': 'Valutakursförluster',
-  '3960': 'Valutakursvinster',
+  '8310': 'Ränteintäkter',
+  '8410': 'Räntekostnader',
 }
 
 /**