feat: remove AI extensions, restructure settings, and add atomic voucher commits (#157)

Remove AI-dependent extensions (ai-chat, ai-categorization, receipt-ocr,
invoice-inbox) and their infrastructure (lib/ai/*, ai-consent, LangChain/
Anthropic/OpenAI deps) to simplify core and reduce bundle size.

Restructure monolithic settings page into dedicated sub-pages (company,
bookkeeping, invoicing, tax, banking, api, account, team, templates) with
shared layout and sidebar navigation.

Add atomic commit_journal_entry RPC so voucher number increment and status
update happen in a single transaction — prevents burned numbers on constraint
failures. Add continuity check report and voucher gap explanation tracking.

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

components/extensions/general/EnableBankingWorkspace.tsx

@@ -14,7 +14,7 @@ export default function EnableBankingWorkspace({ userId }: WorkspaceComponentPro
         Koppla ditt bankkonto under Inställningar för att synka transaktioner automatiskt.
       </p>
       <Button asChild variant="outline" className="mt-4">
-        <Link href="/settings?tab=banking">
+        <Link href="/settings/banking">
           <Settings className="mr-2 h-4 w-4" />
           Gå till bankinställningar
         </Link>