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/SIEPreviewStep.tsx

@@ -99,7 +99,7 @@ export default function SIEPreviewStep({
       </Card>
 
       {/* Statistics */}
-      <div className="grid gap-4 md:grid-cols-4">
+      <div className="grid grid-cols-2 gap-4 md:grid-cols-4">
         <Card>
           <CardContent className="pt-6">
             <div className="flex items-center gap-2 text-muted-foreground mb-1">
@@ -201,7 +201,7 @@ export default function SIEPreviewStep({
           </CardDescription>
         </CardHeader>
         <CardContent>
-          <div className="grid gap-4 md:grid-cols-4">
+          <div className="grid grid-cols-2 gap-4 md:grid-cols-4">
             <div>
               <p className="text-sm text-muted-foreground">Totalt</p>
               <p className="font-medium">{preview.mappingStatus.total}</p>
@@ -303,11 +303,11 @@ export default function SIEPreviewStep({
       )}
 
       {/* Actions */}
-      <div className="flex justify-between">
-        <Button variant="outline" onClick={onBack}>
+      <div className="flex flex-col-reverse gap-3 sm:flex-row sm:justify-between">
+        <Button variant="outline" className="min-h-11" onClick={onBack}>
           Tillbaka
         </Button>
-        <Button onClick={onContinue} disabled={hasBlockingErrors}>
+        <Button className="min-h-11" onClick={onContinue} disabled={hasBlockingErrors}>
           {preview.mappingStatus.lowConfidence > 0 || preview.mappingStatus.unmapped > 0
             ? 'Granska mappningar'
             : 'Fortsätt'}