feat: import system improvements, INK2 fix, and Swedish text corrections (#10)

- SIE parser: Windows-1252 and CP437 encoding detection and decoding
- Bank file parser: add Nordea Business (Företag) CSV format
- Bank file parser: improve format detection for SEB, Länsförsäkringar, generic CSV
- INK2 engine: calculate årets resultat (7222) from income statement for open fiscal years
- Dashboard: parallel Supabase queries, simplified dashboard page
- Fix Swedish characters (å, ä, ö) in BAS data descriptions, validation messages, AI consent disclosures
- Import wizard UI improvements across all steps
- Migration: add 'bas_range' match type to sie_account_mappings constraint
- Extensive new tests for SIE parser encoding and bank file parser

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

components/import/BankFileConfirmStep.tsx

@@ -112,12 +112,13 @@ export default function BankFileConfirmStep({
       </Card>
 
       {/* Actions */}
-      <div className="flex justify-between">
-        <Button variant="outline" onClick={onBack} disabled={isLoading}>
+      <div className="flex flex-col-reverse gap-3 sm:flex-row sm:justify-between">
+        <Button variant="outline" className="min-h-11" onClick={onBack} disabled={isLoading}>
           <ArrowLeft className="mr-2 h-4 w-4" />
           Tillbaka
         </Button>
         <Button
+          className="min-h-11"
           onClick={() => onExecute({
             skip_duplicates: true,
             auto_categorize: false,